diff mbox

[v2,05/13] arm64: kvm: deal with kernel symbols outside of linear mapping

Message ID 1451489172-17420-6-git-send-email-ard.biesheuvel@linaro.org
State New
Headers show

Commit Message

Ard Biesheuvel Dec. 30, 2015, 3:26 p.m. UTC 
KVM on arm64 uses a fixed offset between the linear mapping at EL1 and
the HYP mapping at EL2. Before we can move the kernel virtual mapping
out of the linear mapping, we have to make sure that references to kernel
symbols that are accessed via the HYP mapping are translated to their
linear equivalent.

To prevent inadvertent direct references from sneaking in later, change
the type of all extern declarations to HYP kernel symbols to the opaque
'struct kvm_ksym', which does not decay to a pointer type like char arrays
and function references. This is not bullet proof, but at least forces the
user to take the address explicitly rather than referencing it directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

---
 arch/arm/include/asm/kvm_asm.h   |  2 ++
 arch/arm/include/asm/kvm_mmu.h   |  2 ++
 arch/arm/kvm/arm.c               |  9 +++++----
 arch/arm/kvm/mmu.c               | 12 +++++------
 arch/arm64/include/asm/kvm_asm.h | 21 +++++++++++---------
 arch/arm64/include/asm/kvm_mmu.h |  2 ++
 arch/arm64/include/asm/virt.h    |  4 ----
 arch/arm64/kernel/vmlinux.lds.S  |  4 ++--
 arch/arm64/kvm/debug.c           |  4 +++-
 virt/kvm/arm/vgic-v3.c           |  2 +-
 10 files changed, 34 insertions(+), 28 deletions(-)

-- 
2.5.0

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Comments

Ard Biesheuvel Jan. 4, 2016, 10:31 a.m. UTC | #1 
On 4 January 2016 at 11:08, Marc Zyngier <marc.zyngier@arm.com> wrote:
> Hi Ard,

>

> On 30/12/15 15:26, Ard Biesheuvel wrote:

>> KVM on arm64 uses a fixed offset between the linear mapping at EL1 and

>> the HYP mapping at EL2. Before we can move the kernel virtual mapping

>> out of the linear mapping, we have to make sure that references to kernel

>> symbols that are accessed via the HYP mapping are translated to their

>> linear equivalent.

>>

>> To prevent inadvertent direct references from sneaking in later, change

>> the type of all extern declarations to HYP kernel symbols to the opaque

>> 'struct kvm_ksym', which does not decay to a pointer type like char arrays

>> and function references. This is not bullet proof, but at least forces the

>> user to take the address explicitly rather than referencing it directly.

>>

>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>

> This looks good to me, a few comments below.

>

>> ---

>>  arch/arm/include/asm/kvm_asm.h   |  2 ++

>>  arch/arm/include/asm/kvm_mmu.h   |  2 ++

>>  arch/arm/kvm/arm.c               |  9 +++++----

>>  arch/arm/kvm/mmu.c               | 12 +++++------

>>  arch/arm64/include/asm/kvm_asm.h | 21 +++++++++++---------

>>  arch/arm64/include/asm/kvm_mmu.h |  2 ++

>>  arch/arm64/include/asm/virt.h    |  4 ----

>>  arch/arm64/kernel/vmlinux.lds.S  |  4 ++--

>>  arch/arm64/kvm/debug.c           |  4 +++-

>>  virt/kvm/arm/vgic-v3.c           |  2 +-

>>  10 files changed, 34 insertions(+), 28 deletions(-)

>>

>> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h

>> index 194c91b610ff..484ffdf7c70b 100644

>> --- a/arch/arm/include/asm/kvm_asm.h

>> +++ b/arch/arm/include/asm/kvm_asm.h

>> @@ -99,6 +99,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

>>  extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

>>

>>  extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

>> +

>> +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

>>  #endif

>>

>>  #endif /* __ARM_KVM_ASM_H__ */

>> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h

>> index 405aa1883307..412b363f79e9 100644

>> --- a/arch/arm/include/asm/kvm_mmu.h

>> +++ b/arch/arm/include/asm/kvm_mmu.h

>> @@ -30,6 +30,8 @@

>>  #define HYP_PAGE_OFFSET              PAGE_OFFSET

>>  #define KERN_TO_HYP(kva)     (kva)

>>

>> +#define kvm_ksym_ref(kva)    (kva)

>> +

>>  /*

>>   * Our virtual mapping for the boot-time MMU-enable code. Must be

>>   * shared across all the page-tables. Conveniently, we use the vectors

>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c

>> index e06fd299de08..014b542ea658 100644

>> --- a/arch/arm/kvm/arm.c

>> +++ b/arch/arm/kvm/arm.c

>> @@ -427,7 +42You can use it, but you don't have to, since yo7,7 @@ static void update_vttbr(struct kvm *kvm)

>>                * shareable domain to make sure all data structures are

>>                * clean.

>>                */

>> -             kvm_call_hyp(__kvm_flush_vm_context);

>> +             kvm_call_hyp(kvm_ksym_ref(__kvm_flush_vm_context));

>>       }

>>

>>       kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);

>> @@ -600,7 +600,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

>>               __kvm_guest_enter();

>>               vcpu->mode = IN_GUEST_MODE;

>>

>> -             ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);

>> +             ret = kvm_call_hyp(kvm_ksym_ref(__kvm_vcpu_run), vcpu);

>>

>>               vcpu->mode = OUTSIDE_GUEST_MODE;

>>               /*

>> @@ -969,7 +969,7 @@ static void cpu_init_hyp_mode(void *dummy)

>>       pgd_ptr = kvm_mmu_get_httbr();

>>       stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);

>>       hyp_stack_ptr = stack_page + PAGE_SIZE;

>> -     vector_ptr = (unsigned long)__kvm_hyp_vector;

>> +     vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);

>>

>>       __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);

>>

>> @@ -1061,7 +1061,8 @@ static int init_hyp_mode(void)

>>       /*

>>        * Map the Hyp-code called directly from the host

>>        */

>> -     err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);

>> +     err = create_hyp_mappings(kvm_ksym_ref(__kvm_hyp_code_start),

>> +                               kvm_ksym_ref(__kvm_hyp_code_end));

>>       if (err) {

>>               kvm_err("Cannot map world-switch code\n");

>>               goto out_free_mappings;

>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c

>> index 7dace909d5cf..7c448b943e3a 100644

>> --- a/arch/arm/kvm/mmu.c

>> +++ b/arch/arm/kvm/mmu.c

>> @@ -31,8 +31,6 @@

>>

>>  #include "trace.h"

>>

>> -extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];

>> -

>>  static pgd_t *boot_hyp_pgd;

>>  static pgd_t *hyp_pgd;

>>  static pgd_t *merged_hyp_pgd;

>> @@ -63,7 +61,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)

>>   */

>>  void kvm_flush_remote_tlbs(struct kvm *kvm)

>>  {

>> -     kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);

>> +     kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid), kvm);

>

> Any chance we could bury kvm_ksym_ref in kvm_call_hyp? It may make the

> change more readable, but I have the feeling it would require an

> intermediate #define...

>


Yes, we'd have to rename the actual kvm_call_hyp definition so we can
wrap it in a macro

And the call in __cpu_init_hyp_mode() would need to omit the macro,
since it passes a pointer into the linear mapping, not a kernel
symbol.
So if you think that's ok, I'm happy to change that.

>>  }

>>

>>  static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

>> @@ -75,7 +73,7 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

>>        * anything there.

>>        */

>>       if (kvm)

>> -             kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);

>> +             kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid_ipa), kvm, ipa);

>>  }

>>

>>  /*

>> @@ -1647,9 +1645,9 @@ int kvm_mmu_init(void)

>>  {

>>       int err;

>>

>> -     hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);

>> -     hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);

>> -     hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);

>> +     hyp_idmap_start = kvm_virt_to_phys(&__hyp_idmap_text_start);

>> +     hyp_idmap_end = kvm_virt_to_phys(&__hyp_idmap_text_end);

>> +     hyp_idmap_vector = kvm_virt_to_phys(&__kvm_hyp_init);

>

> Why don't you need to use kvm_ksym_ref here? Is the idmap treated

> differently?

>


No, but we are taking the physical address, which ultimately produces
the same value whether we use kvm_ksym_ref() or not.

>>

>>       /*

>>        * We rely on the linker script to ensure at build time that the HYP

>> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h

>> index 5e377101f919..830402f847e0 100644

>> --- a/arch/arm64/include/asm/kvm_asm.h

>> +++ b/arch/arm64/include/asm/kvm_asm.h

>> @@ -105,24 +105,27 @@

>>  #ifndef __ASSEMBLY__

>>  struct kvm;

>>  struct kvm_vcpu;

>> +struct kvm_ksym;

>

> And that's it? Never actually defined? That's cunning! ;-)

>

>>

>>  extern char __kvm_hyp_init[];

>>  extern char __kvm_hyp_init_end[];

>>

>> -extern char __kvm_hyp_vector[];

>> +extern struct kvm_ksym __kvm_hyp_vector;

>>

>> -#define      __kvm_hyp_code_start    __hyp_text_start

>> -#define      __kvm_hyp_code_end      __hyp_text_end

>> +extern struct kvm_ksym __kvm_hyp_code_start;

>> +extern struct kvm_ksym __kvm_hyp_code_end;

>>

>> -extern void __kvm_flush_vm_context(void);

>> -extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

>> -extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

>> +extern struct kvm_ksym __kvm_flush_vm_context;

>> +extern struct kvm_ksym __kvm_tlb_flush_vmid_ipa;

>> +extern struct kvm_ksym __kvm_tlb_flush_vmid;

>>

>> -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

>> +extern struct kvm_ksym __kvm_vcpu_run;

>>

>> -extern u64 __vgic_v3_get_ich_vtr_el2(void);

>> +extern struct kvm_ksym __hyp_idmap_text_start, __hyp_idmap_text_end;

>>

>> -extern u32 __kvm_get_mdcr_el2(void);

>> +extern struct kvm_ksym __vgic_v3_get_ich_vtr_el2;

>> +

>> +extern struct kvm_ksym __kvm_get_mdcr_el2;

>>

>>  #endif

>>

>> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h

>> index 61505676d085..0899026a2821 100644

>> --- a/arch/arm64/include/asm/kvm_mmu.h

>> +++ b/arch/arm64/include/asm/kvm_mmu.h

>> @@ -73,6 +73,8 @@

>>

>>  #define KERN_TO_HYP(kva)     ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

>>

>> +#define kvm_ksym_ref(sym)    ((void *)&sym - KIMAGE_VADDR + PAGE_OFFSET)

>> +

>>  /*

>>   * We currently only support a 40bit IPA.

>>   */

>> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h

>> index 7a5df5252dd7..215ad4649dd7 100644

>> --- a/arch/arm64/include/asm/virt.h

>> +++ b/arch/arm64/include/asm/virt.h

>> @@ -50,10 +50,6 @@ static inline bool is_hyp_mode_mismatched(void)

>>       return __boot_cpu_mode[0] != __boot_cpu_mode[1];

>>  }

>>

>> -/* The section containing the hypervisor text */

>> -extern char __hyp_text_start[];

>> -extern char __hyp_text_end[];

>> -

>>  #endif /* __ASSEMBLY__ */

>>

>>  #endif /* ! __ASM__VIRT_H */

>> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S

>> index 363c2f529951..f935f082188d 100644

>> --- a/arch/arm64/kernel/vmlinux.lds.S

>> +++ b/arch/arm64/kernel/vmlinux.lds.S

>> @@ -35,9 +35,9 @@ jiffies = jiffies_64;

>>       VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;     \

>>       *(.hyp.idmap.text)                              \

>>       VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;       \

>> -     VMLINUX_SYMBOL(__hyp_text_start) = .;           \

>> +     VMLINUX_SYMBOL(__kvm_hyp_code_start) = .;       \

>>       *(.hyp.text)                                    \

>> -     VMLINUX_SYMBOL(__hyp_text_end) = .;

>> +     VMLINUX_SYMBOL(__kvm_hyp_code_end) = .;

>

> I have a couple of patches going in the exact opposite direction (making

> arm more similar to arm64):

>

> http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/commit/?h=kvm-arm/wsinc&id=94a3d4d4ff1d8ad59f9150dfa9fdd1685ab03950

> http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/commit/?h=kvm-arm/wsinc&id=44aec57b62dca67cf91f425e3707f257b9bbeb18

>

> As at least the first patch is required to convert the 32bit HYP code to

> C, I'd rather not change this in the 64bit code.

>


OK, I will align with those changes instead.


>>

>>  #define IDMAP_TEXT                                   \

>>       . = ALIGN(SZ_4K);                               \

>> diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c

>> index 47e5f0feaee8..99e5a403af4e 100644

>> --- a/arch/arm64/kvm/debug.c

>> +++ b/arch/arm64/kvm/debug.c

>> @@ -24,6 +24,7 @@

>>  #include <asm/kvm_asm.h>

>>  #include <asm/kvm_arm.h>

>>  #include <asm/kvm_emulate.h>

>> +#include <asm/kvm_mmu.h>

>>

>>  #include "trace.h"

>>

>> @@ -72,7 +73,8 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu)

>>

>>  void kvm_arm_init_debug(void)

>>  {

>> -     __this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2));

>> +     __this_cpu_write(mdcr_el2,

>> +                      kvm_call_hyp(kvm_ksym_ref(__kvm_get_mdcr_el2)));

>>  }

>>

>>  /**

>> diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c

>> index 487d6357b7e7..58f5a6521307 100644

>> --- a/virt/kvm/arm/vgic-v3.c

>> +++ b/virt/kvm/arm/vgic-v3.c

>> @@ -247,7 +247,7 @@ int vgic_v3_probe(struct device_node *vgic_node,

>>               goto out;

>>       }

>>

>> -     ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);

>> +     ich_vtr_el2 = kvm_call_hyp(kvm_ksym_ref(__vgic_v3_get_ich_vtr_el2));

>>

>>       /*

>>        * The ListRegs field is 5 bits, but there is a architectural

>>

>

> Thanks,

>

>         M.

> --

> Jazz is not dead. It just smells funny...

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Christoffer Dall Jan. 5, 2016, 2:41 p.m. UTC | #2 
On Wed, Dec 30, 2015 at 04:26:04PM +0100, Ard Biesheuvel wrote:
> KVM on arm64 uses a fixed offset between the linear mapping at EL1 and

> the HYP mapping at EL2. Before we can move the kernel virtual mapping

> out of the linear mapping, we have to make sure that references to kernel

> symbols that are accessed via the HYP mapping are translated to their

> linear equivalent.

> 

> To prevent inadvertent direct references from sneaking in later, change

> the type of all extern declarations to HYP kernel symbols to the opaque

> 'struct kvm_ksym', which does not decay to a pointer type like char arrays

> and function references. This is not bullet proof, but at least forces the

> user to take the address explicitly rather than referencing it directly.

> 

> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> ---

>  arch/arm/include/asm/kvm_asm.h   |  2 ++

>  arch/arm/include/asm/kvm_mmu.h   |  2 ++

>  arch/arm/kvm/arm.c               |  9 +++++----

>  arch/arm/kvm/mmu.c               | 12 +++++------

>  arch/arm64/include/asm/kvm_asm.h | 21 +++++++++++---------

>  arch/arm64/include/asm/kvm_mmu.h |  2 ++

>  arch/arm64/include/asm/virt.h    |  4 ----

>  arch/arm64/kernel/vmlinux.lds.S  |  4 ++--

>  arch/arm64/kvm/debug.c           |  4 +++-

>  virt/kvm/arm/vgic-v3.c           |  2 +-

>  10 files changed, 34 insertions(+), 28 deletions(-)

> 

> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h

> index 194c91b610ff..484ffdf7c70b 100644

> --- a/arch/arm/include/asm/kvm_asm.h

> +++ b/arch/arm/include/asm/kvm_asm.h

> @@ -99,6 +99,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

>  extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

>  

>  extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

> +

> +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

>  #endif

>  

>  #endif /* __ARM_KVM_ASM_H__ */

> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h

> index 405aa1883307..412b363f79e9 100644

> --- a/arch/arm/include/asm/kvm_mmu.h

> +++ b/arch/arm/include/asm/kvm_mmu.h

> @@ -30,6 +30,8 @@

>  #define HYP_PAGE_OFFSET		PAGE_OFFSET

>  #define KERN_TO_HYP(kva)	(kva)

>  

> +#define kvm_ksym_ref(kva)	(kva)

> +

>  /*

>   * Our virtual mapping for the boot-time MMU-enable code. Must be

>   * shared across all the page-tables. Conveniently, we use the vectors

> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c

> index e06fd299de08..014b542ea658 100644

> --- a/arch/arm/kvm/arm.c

> +++ b/arch/arm/kvm/arm.c

> @@ -427,7 +427,7 @@ static void update_vttbr(struct kvm *kvm)

>  		 * shareable domain to make sure all data structures are

>  		 * clean.

>  		 */

> -		kvm_call_hyp(__kvm_flush_vm_context);

> +		kvm_call_hyp(kvm_ksym_ref(__kvm_flush_vm_context));

>  	}

>  

>  	kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);

> @@ -600,7 +600,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

>  		__kvm_guest_enter();

>  		vcpu->mode = IN_GUEST_MODE;

>  

> -		ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);

> +		ret = kvm_call_hyp(kvm_ksym_ref(__kvm_vcpu_run), vcpu);

>  

>  		vcpu->mode = OUTSIDE_GUEST_MODE;

>  		/*

> @@ -969,7 +969,7 @@ static void cpu_init_hyp_mode(void *dummy)

>  	pgd_ptr = kvm_mmu_get_httbr();

>  	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);

>  	hyp_stack_ptr = stack_page + PAGE_SIZE;

> -	vector_ptr = (unsigned long)__kvm_hyp_vector;

> +	vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);

>  

>  	__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);

>  

> @@ -1061,7 +1061,8 @@ static int init_hyp_mode(void)

>  	/*

>  	 * Map the Hyp-code called directly from the host

>  	 */

> -	err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);

> +	err = create_hyp_mappings(kvm_ksym_ref(__kvm_hyp_code_start),

> +				  kvm_ksym_ref(__kvm_hyp_code_end));

>  	if (err) {

>  		kvm_err("Cannot map world-switch code\n");

>  		goto out_free_mappings;

> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c

> index 7dace909d5cf..7c448b943e3a 100644

> --- a/arch/arm/kvm/mmu.c

> +++ b/arch/arm/kvm/mmu.c

> @@ -31,8 +31,6 @@

>  

>  #include "trace.h"

>  

> -extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];

> -

>  static pgd_t *boot_hyp_pgd;

>  static pgd_t *hyp_pgd;

>  static pgd_t *merged_hyp_pgd;

> @@ -63,7 +61,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)

>   */

>  void kvm_flush_remote_tlbs(struct kvm *kvm)

>  {

> -	kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);

> +	kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid), kvm);

>  }

>  

>  static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

> @@ -75,7 +73,7 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

>  	 * anything there.

>  	 */

>  	if (kvm)

> -		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);

> +		kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid_ipa), kvm, ipa);

>  }

>  

>  /*

> @@ -1647,9 +1645,9 @@ int kvm_mmu_init(void)

>  {

>  	int err;

>  

> -	hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);

> -	hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);

> -	hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);

> +	hyp_idmap_start = kvm_virt_to_phys(&__hyp_idmap_text_start);

> +	hyp_idmap_end = kvm_virt_to_phys(&__hyp_idmap_text_end);

> +	hyp_idmap_vector = kvm_virt_to_phys(&__kvm_hyp_init);

>  

>  	/*

>  	 * We rely on the linker script to ensure at build time that the HYP

> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h

> index 5e377101f919..830402f847e0 100644

> --- a/arch/arm64/include/asm/kvm_asm.h

> +++ b/arch/arm64/include/asm/kvm_asm.h

> @@ -105,24 +105,27 @@

>  #ifndef __ASSEMBLY__

>  struct kvm;

>  struct kvm_vcpu;

> +struct kvm_ksym;

>  

>  extern char __kvm_hyp_init[];

>  extern char __kvm_hyp_init_end[];

>  

> -extern char __kvm_hyp_vector[];

> +extern struct kvm_ksym __kvm_hyp_vector;

>  

> -#define	__kvm_hyp_code_start	__hyp_text_start

> -#define	__kvm_hyp_code_end	__hyp_text_end

> +extern struct kvm_ksym __kvm_hyp_code_start;

> +extern struct kvm_ksym __kvm_hyp_code_end;

>  

> -extern void __kvm_flush_vm_context(void);

> -extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

> -extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

> +extern struct kvm_ksym __kvm_flush_vm_context;

> +extern struct kvm_ksym __kvm_tlb_flush_vmid_ipa;

> +extern struct kvm_ksym __kvm_tlb_flush_vmid;

>  

> -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

> +extern struct kvm_ksym __kvm_vcpu_run;

>  

> -extern u64 __vgic_v3_get_ich_vtr_el2(void);

> +extern struct kvm_ksym __hyp_idmap_text_start, __hyp_idmap_text_end;

>  

> -extern u32 __kvm_get_mdcr_el2(void);

> +extern struct kvm_ksym __vgic_v3_get_ich_vtr_el2;

> +

> +extern struct kvm_ksym __kvm_get_mdcr_el2;

>  

>  #endif

>  

> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h

> index 61505676d085..0899026a2821 100644

> --- a/arch/arm64/include/asm/kvm_mmu.h

> +++ b/arch/arm64/include/asm/kvm_mmu.h

> @@ -73,6 +73,8 @@

>  

>  #define KERN_TO_HYP(kva)	((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

>  

> +#define kvm_ksym_ref(sym)	((void *)&sym - KIMAGE_VADDR + PAGE_OFFSET)

> +

>  /*

>   * We currently only support a 40bit IPA.

>   */

> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h

> index 7a5df5252dd7..215ad4649dd7 100644

> --- a/arch/arm64/include/asm/virt.h

> +++ b/arch/arm64/include/asm/virt.h

> @@ -50,10 +50,6 @@ static inline bool is_hyp_mode_mismatched(void)

>  	return __boot_cpu_mode[0] != __boot_cpu_mode[1];

>  }

>  

> -/* The section containing the hypervisor text */

> -extern char __hyp_text_start[];

> -extern char __hyp_text_end[];

> -

>  #endif /* __ASSEMBLY__ */

>  

>  #endif /* ! __ASM__VIRT_H */

> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S

> index 363c2f529951..f935f082188d 100644

> --- a/arch/arm64/kernel/vmlinux.lds.S

> +++ b/arch/arm64/kernel/vmlinux.lds.S

> @@ -35,9 +35,9 @@ jiffies = jiffies_64;

>  	VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;	\

>  	*(.hyp.idmap.text)				\

>  	VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;	\

> -	VMLINUX_SYMBOL(__hyp_text_start) = .;		\

> +	VMLINUX_SYMBOL(__kvm_hyp_code_start) = .;	\

>  	*(.hyp.text)					\

> -	VMLINUX_SYMBOL(__hyp_text_end) = .;

> +	VMLINUX_SYMBOL(__kvm_hyp_code_end) = .;


why this rename?

-Christoffer
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Ard Biesheuvel Jan. 5, 2016, 2:51 p.m. UTC | #3 
On 5 January 2016 at 15:41, Christoffer Dall
<christoffer.dall@linaro.org> wrote:
> On Wed, Dec 30, 2015 at 04:26:04PM +0100, Ard Biesheuvel wrote:

>> KVM on arm64 uses a fixed offset between the linear mapping at EL1 and

>> the HYP mapping at EL2. Before we can move the kernel virtual mapping

>> out of the linear mapping, we have to make sure that references to kernel

>> symbols that are accessed via the HYP mapping are translated to their

>> linear equivalent.

>>

>> To prevent inadvertent direct references from sneaking in later, change

>> the type of all extern declarations to HYP kernel symbols to the opaque

>> 'struct kvm_ksym', which does not decay to a pointer type like char arrays

>> and function references. This is not bullet proof, but at least forces the

>> user to take the address explicitly rather than referencing it directly.

>>

>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

>> ---

>>  arch/arm/include/asm/kvm_asm.h   |  2 ++

>>  arch/arm/include/asm/kvm_mmu.h   |  2 ++

>>  arch/arm/kvm/arm.c               |  9 +++++----

>>  arch/arm/kvm/mmu.c               | 12 +++++------

>>  arch/arm64/include/asm/kvm_asm.h | 21 +++++++++++---------

>>  arch/arm64/include/asm/kvm_mmu.h |  2 ++

>>  arch/arm64/include/asm/virt.h    |  4 ----

>>  arch/arm64/kernel/vmlinux.lds.S  |  4 ++--

>>  arch/arm64/kvm/debug.c           |  4 +++-

>>  virt/kvm/arm/vgic-v3.c           |  2 +-

>>  10 files changed, 34 insertions(+), 28 deletions(-)

>>

>> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h

>> index 194c91b610ff..484ffdf7c70b 100644

>> --- a/arch/arm/include/asm/kvm_asm.h

>> +++ b/arch/arm/include/asm/kvm_asm.h

>> @@ -99,6 +99,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

>>  extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

>>

>>  extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

>> +

>> +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

>>  #endif

>>

>>  #endif /* __ARM_KVM_ASM_H__ */

>> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h

>> index 405aa1883307..412b363f79e9 100644

>> --- a/arch/arm/include/asm/kvm_mmu.h

>> +++ b/arch/arm/include/asm/kvm_mmu.h

>> @@ -30,6 +30,8 @@

>>  #define HYP_PAGE_OFFSET              PAGE_OFFSET

>>  #define KERN_TO_HYP(kva)     (kva)

>>

>> +#define kvm_ksym_ref(kva)    (kva)

>> +

>>  /*

>>   * Our virtual mapping for the boot-time MMU-enable code. Must be

>>   * shared across all the page-tables. Conveniently, we use the vectors

>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c

>> index e06fd299de08..014b542ea658 100644

>> --- a/arch/arm/kvm/arm.c

>> +++ b/arch/arm/kvm/arm.c

>> @@ -427,7 +427,7 @@ static void update_vttbr(struct kvm *kvm)

>>                * shareable domain to make sure all data structures are

>>                * clean.

>>                */

>> -             kvm_call_hyp(__kvm_flush_vm_context);

>> +             kvm_call_hyp(kvm_ksym_ref(__kvm_flush_vm_context));

>>       }

>>

>>       kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);

>> @@ -600,7 +600,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

>>               __kvm_guest_enter();

>>               vcpu->mode = IN_GUEST_MODE;

>>

>> -             ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);

>> +             ret = kvm_call_hyp(kvm_ksym_ref(__kvm_vcpu_run), vcpu);

>>

>>               vcpu->mode = OUTSIDE_GUEST_MODE;

>>               /*

>> @@ -969,7 +969,7 @@ static void cpu_init_hyp_mode(void *dummy)

>>       pgd_ptr = kvm_mmu_get_httbr();

>>       stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);

>>       hyp_stack_ptr = stack_page + PAGE_SIZE;

>> -     vector_ptr = (unsigned long)__kvm_hyp_vector;

>> +     vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);

>>

>>       __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);

>>

>> @@ -1061,7 +1061,8 @@ static int init_hyp_mode(void)

>>       /*

>>        * Map the Hyp-code called directly from the host

>>        */

>> -     err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);

>> +     err = create_hyp_mappings(kvm_ksym_ref(__kvm_hyp_code_start),

>> +                               kvm_ksym_ref(__kvm_hyp_code_end));

>>       if (err) {

>>               kvm_err("Cannot map world-switch code\n");

>>               goto out_free_mappings;

>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c

>> index 7dace909d5cf..7c448b943e3a 100644

>> --- a/arch/arm/kvm/mmu.c

>> +++ b/arch/arm/kvm/mmu.c

>> @@ -31,8 +31,6 @@

>>

>>  #include "trace.h"

>>

>> -extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];

>> -

>>  static pgd_t *boot_hyp_pgd;

>>  static pgd_t *hyp_pgd;

>>  static pgd_t *merged_hyp_pgd;

>> @@ -63,7 +61,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)

>>   */

>>  void kvm_flush_remote_tlbs(struct kvm *kvm)

>>  {

>> -     kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);

>> +     kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid), kvm);

>>  }

>>

>>  static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

>> @@ -75,7 +73,7 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

>>        * anything there.

>>        */

>>       if (kvm)

>> -             kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);

>> +             kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid_ipa), kvm, ipa);

>>  }

>>

>>  /*

>> @@ -1647,9 +1645,9 @@ int kvm_mmu_init(void)

>>  {

>>       int err;

>>

>> -     hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);

>> -     hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);

>> -     hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);

>> +     hyp_idmap_start = kvm_virt_to_phys(&__hyp_idmap_text_start);

>> +     hyp_idmap_end = kvm_virt_to_phys(&__hyp_idmap_text_end);

>> +     hyp_idmap_vector = kvm_virt_to_phys(&__kvm_hyp_init);

>>

>>       /*

>>        * We rely on the linker script to ensure at build time that the HYP

>> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h

>> index 5e377101f919..830402f847e0 100644

>> --- a/arch/arm64/include/asm/kvm_asm.h

>> +++ b/arch/arm64/include/asm/kvm_asm.h

>> @@ -105,24 +105,27 @@

>>  #ifndef __ASSEMBLY__

>>  struct kvm;

>>  struct kvm_vcpu;

>> +struct kvm_ksym;

>>

>>  extern char __kvm_hyp_init[];

>>  extern char __kvm_hyp_init_end[];

>>

>> -extern char __kvm_hyp_vector[];

>> +extern struct kvm_ksym __kvm_hyp_vector;

>>

>> -#define      __kvm_hyp_code_start    __hyp_text_start

>> -#define      __kvm_hyp_code_end      __hyp_text_end

>> +extern struct kvm_ksym __kvm_hyp_code_start;

>> +extern struct kvm_ksym __kvm_hyp_code_end;

>>

>> -extern void __kvm_flush_vm_context(void);

>> -extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

>> -extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

>> +extern struct kvm_ksym __kvm_flush_vm_context;

>> +extern struct kvm_ksym __kvm_tlb_flush_vmid_ipa;

>> +extern struct kvm_ksym __kvm_tlb_flush_vmid;

>>

>> -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

>> +extern struct kvm_ksym __kvm_vcpu_run;

>>

>> -extern u64 __vgic_v3_get_ich_vtr_el2(void);

>> +extern struct kvm_ksym __hyp_idmap_text_start, __hyp_idmap_text_end;

>>

>> -extern u32 __kvm_get_mdcr_el2(void);

>> +extern struct kvm_ksym __vgic_v3_get_ich_vtr_el2;

>> +

>> +extern struct kvm_ksym __kvm_get_mdcr_el2;

>>

>>  #endif

>>

>> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h

>> index 61505676d085..0899026a2821 100644

>> --- a/arch/arm64/include/asm/kvm_mmu.h

>> +++ b/arch/arm64/include/asm/kvm_mmu.h

>> @@ -73,6 +73,8 @@

>>

>>  #define KERN_TO_HYP(kva)     ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

>>

>> +#define kvm_ksym_ref(sym)    ((void *)&sym - KIMAGE_VADDR + PAGE_OFFSET)

>> +

>>  /*

>>   * We currently only support a 40bit IPA.

>>   */

>> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h

>> index 7a5df5252dd7..215ad4649dd7 100644

>> --- a/arch/arm64/include/asm/virt.h

>> +++ b/arch/arm64/include/asm/virt.h

>> @@ -50,10 +50,6 @@ static inline bool is_hyp_mode_mismatched(void)

>>       return __boot_cpu_mode[0] != __boot_cpu_mode[1];

>>  }

>>

>> -/* The section containing the hypervisor text */

>> -extern char __hyp_text_start[];

>> -extern char __hyp_text_end[];

>> -

>>  #endif /* __ASSEMBLY__ */

>>

>>  #endif /* ! __ASM__VIRT_H */

>> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S

>> index 363c2f529951..f935f082188d 100644

>> --- a/arch/arm64/kernel/vmlinux.lds.S

>> +++ b/arch/arm64/kernel/vmlinux.lds.S

>> @@ -35,9 +35,9 @@ jiffies = jiffies_64;

>>       VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;     \

>>       *(.hyp.idmap.text)                              \

>>       VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;       \

>> -     VMLINUX_SYMBOL(__hyp_text_start) = .;           \

>> +     VMLINUX_SYMBOL(__kvm_hyp_code_start) = .;       \

>>       *(.hyp.text)                                    \

>> -     VMLINUX_SYMBOL(__hyp_text_end) = .;

>> +     VMLINUX_SYMBOL(__kvm_hyp_code_end) = .;

>

> why this rename?

>


I already got rid of it based on Marc's feedback. The only reason was
to align between ARM and arm64, but he is already doing the same in
the opposite direction
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Christoffer Dall Jan. 5, 2016, 2:56 p.m. UTC | #4 
On Tue, Jan 05, 2016 at 03:51:58PM +0100, Ard Biesheuvel wrote:
> On 5 January 2016 at 15:41, Christoffer Dall

> <christoffer.dall@linaro.org> wrote:

> > On Wed, Dec 30, 2015 at 04:26:04PM +0100, Ard Biesheuvel wrote:

> >> KVM on arm64 uses a fixed offset between the linear mapping at EL1 and

> >> the HYP mapping at EL2. Before we can move the kernel virtual mapping

> >> out of the linear mapping, we have to make sure that references to kernel

> >> symbols that are accessed via the HYP mapping are translated to their

> >> linear equivalent.

> >>

> >> To prevent inadvertent direct references from sneaking in later, change

> >> the type of all extern declarations to HYP kernel symbols to the opaque

> >> 'struct kvm_ksym', which does not decay to a pointer type like char arrays

> >> and function references. This is not bullet proof, but at least forces the

> >> user to take the address explicitly rather than referencing it directly.

> >>

> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

> >> ---

> >>  arch/arm/include/asm/kvm_asm.h   |  2 ++

> >>  arch/arm/include/asm/kvm_mmu.h   |  2 ++

> >>  arch/arm/kvm/arm.c               |  9 +++++----

> >>  arch/arm/kvm/mmu.c               | 12 +++++------

> >>  arch/arm64/include/asm/kvm_asm.h | 21 +++++++++++---------

> >>  arch/arm64/include/asm/kvm_mmu.h |  2 ++

> >>  arch/arm64/include/asm/virt.h    |  4 ----

> >>  arch/arm64/kernel/vmlinux.lds.S  |  4 ++--

> >>  arch/arm64/kvm/debug.c           |  4 +++-

> >>  virt/kvm/arm/vgic-v3.c           |  2 +-

> >>  10 files changed, 34 insertions(+), 28 deletions(-)

> >>

> >> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h

> >> index 194c91b610ff..484ffdf7c70b 100644

> >> --- a/arch/arm/include/asm/kvm_asm.h

> >> +++ b/arch/arm/include/asm/kvm_asm.h

> >> @@ -99,6 +99,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

> >>  extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

> >>

> >>  extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

> >> +

> >> +extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

> >>  #endif

> >>

> >>  #endif /* __ARM_KVM_ASM_H__ */

> >> diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h

> >> index 405aa1883307..412b363f79e9 100644

> >> --- a/arch/arm/include/asm/kvm_mmu.h

> >> +++ b/arch/arm/include/asm/kvm_mmu.h

> >> @@ -30,6 +30,8 @@

> >>  #define HYP_PAGE_OFFSET              PAGE_OFFSET

> >>  #define KERN_TO_HYP(kva)     (kva)

> >>

> >> +#define kvm_ksym_ref(kva)    (kva)

> >> +

> >>  /*

> >>   * Our virtual mapping for the boot-time MMU-enable code. Must be

> >>   * shared across all the page-tables. Conveniently, we use the vectors

> >> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c

> >> index e06fd299de08..014b542ea658 100644

> >> --- a/arch/arm/kvm/arm.c

> >> +++ b/arch/arm/kvm/arm.c

> >> @@ -427,7 +427,7 @@ static void update_vttbr(struct kvm *kvm)

> >>                * shareable domain to make sure all data structures are

> >>                * clean.

> >>                */

> >> -             kvm_call_hyp(__kvm_flush_vm_context);

> >> +             kvm_call_hyp(kvm_ksym_ref(__kvm_flush_vm_context));

> >>       }

> >>

> >>       kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);

> >> @@ -600,7 +600,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)

> >>               __kvm_guest_enter();

> >>               vcpu->mode = IN_GUEST_MODE;

> >>

> >> -             ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);

> >> +             ret = kvm_call_hyp(kvm_ksym_ref(__kvm_vcpu_run), vcpu);

> >>

> >>               vcpu->mode = OUTSIDE_GUEST_MODE;

> >>               /*

> >> @@ -969,7 +969,7 @@ static void cpu_init_hyp_mode(void *dummy)

> >>       pgd_ptr = kvm_mmu_get_httbr();

> >>       stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);

> >>       hyp_stack_ptr = stack_page + PAGE_SIZE;

> >> -     vector_ptr = (unsigned long)__kvm_hyp_vector;

> >> +     vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);

> >>

> >>       __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);

> >>

> >> @@ -1061,7 +1061,8 @@ static int init_hyp_mode(void)

> >>       /*

> >>        * Map the Hyp-code called directly from the host

> >>        */

> >> -     err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);

> >> +     err = create_hyp_mappings(kvm_ksym_ref(__kvm_hyp_code_start),

> >> +                               kvm_ksym_ref(__kvm_hyp_code_end));

> >>       if (err) {

> >>               kvm_err("Cannot map world-switch code\n");

> >>               goto out_free_mappings;

> >> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c

> >> index 7dace909d5cf..7c448b943e3a 100644

> >> --- a/arch/arm/kvm/mmu.c

> >> +++ b/arch/arm/kvm/mmu.c

> >> @@ -31,8 +31,6 @@

> >>

> >>  #include "trace.h"

> >>

> >> -extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];

> >> -

> >>  static pgd_t *boot_hyp_pgd;

> >>  static pgd_t *hyp_pgd;

> >>  static pgd_t *merged_hyp_pgd;

> >> @@ -63,7 +61,7 @@ static bool memslot_is_logging(struct kvm_memory_slot *memslot)

> >>   */

> >>  void kvm_flush_remote_tlbs(struct kvm *kvm)

> >>  {

> >> -     kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);

> >> +     kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid), kvm);

> >>  }

> >>

> >>  static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

> >> @@ -75,7 +73,7 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)

> >>        * anything there.

> >>        */

> >>       if (kvm)

> >> -             kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);

> >> +             kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid_ipa), kvm, ipa);

> >>  }

> >>

> >>  /*

> >> @@ -1647,9 +1645,9 @@ int kvm_mmu_init(void)

> >>  {

> >>       int err;

> >>

> >> -     hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);

> >> -     hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);

> >> -     hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);

> >> +     hyp_idmap_start = kvm_virt_to_phys(&__hyp_idmap_text_start);

> >> +     hyp_idmap_end = kvm_virt_to_phys(&__hyp_idmap_text_end);

> >> +     hyp_idmap_vector = kvm_virt_to_phys(&__kvm_hyp_init);

> >>

> >>       /*

> >>        * We rely on the linker script to ensure at build time that the HYP

> >> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h

> >> index 5e377101f919..830402f847e0 100644

> >> --- a/arch/arm64/include/asm/kvm_asm.h

> >> +++ b/arch/arm64/include/asm/kvm_asm.h

> >> @@ -105,24 +105,27 @@

> >>  #ifndef __ASSEMBLY__

> >>  struct kvm;

> >>  struct kvm_vcpu;

> >> +struct kvm_ksym;

> >>

> >>  extern char __kvm_hyp_init[];

> >>  extern char __kvm_hyp_init_end[];

> >>

> >> -extern char __kvm_hyp_vector[];

> >> +extern struct kvm_ksym __kvm_hyp_vector;

> >>

> >> -#define      __kvm_hyp_code_start    __hyp_text_start

> >> -#define      __kvm_hyp_code_end      __hyp_text_end

> >> +extern struct kvm_ksym __kvm_hyp_code_start;

> >> +extern struct kvm_ksym __kvm_hyp_code_end;

> >>

> >> -extern void __kvm_flush_vm_context(void);

> >> -extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);

> >> -extern void __kvm_tlb_flush_vmid(struct kvm *kvm);

> >> +extern struct kvm_ksym __kvm_flush_vm_context;

> >> +extern struct kvm_ksym __kvm_tlb_flush_vmid_ipa;

> >> +extern struct kvm_ksym __kvm_tlb_flush_vmid;

> >>

> >> -extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

> >> +extern struct kvm_ksym __kvm_vcpu_run;

> >>

> >> -extern u64 __vgic_v3_get_ich_vtr_el2(void);

> >> +extern struct kvm_ksym __hyp_idmap_text_start, __hyp_idmap_text_end;

> >>

> >> -extern u32 __kvm_get_mdcr_el2(void);

> >> +extern struct kvm_ksym __vgic_v3_get_ich_vtr_el2;

> >> +

> >> +extern struct kvm_ksym __kvm_get_mdcr_el2;

> >>

> >>  #endif

> >>

> >> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h

> >> index 61505676d085..0899026a2821 100644

> >> --- a/arch/arm64/include/asm/kvm_mmu.h

> >> +++ b/arch/arm64/include/asm/kvm_mmu.h

> >> @@ -73,6 +73,8 @@

> >>

> >>  #define KERN_TO_HYP(kva)     ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

> >>

> >> +#define kvm_ksym_ref(sym)    ((void *)&sym - KIMAGE_VADDR + PAGE_OFFSET)

> >> +

> >>  /*

> >>   * We currently only support a 40bit IPA.

> >>   */

> >> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h

> >> index 7a5df5252dd7..215ad4649dd7 100644

> >> --- a/arch/arm64/include/asm/virt.h

> >> +++ b/arch/arm64/include/asm/virt.h

> >> @@ -50,10 +50,6 @@ static inline bool is_hyp_mode_mismatched(void)

> >>       return __boot_cpu_mode[0] != __boot_cpu_mode[1];

> >>  }

> >>

> >> -/* The section containing the hypervisor text */

> >> -extern char __hyp_text_start[];

> >> -extern char __hyp_text_end[];

> >> -

> >>  #endif /* __ASSEMBLY__ */

> >>

> >>  #endif /* ! __ASM__VIRT_H */

> >> diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S

> >> index 363c2f529951..f935f082188d 100644

> >> --- a/arch/arm64/kernel/vmlinux.lds.S

> >> +++ b/arch/arm64/kernel/vmlinux.lds.S

> >> @@ -35,9 +35,9 @@ jiffies = jiffies_64;

> >>       VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;     \

> >>       *(.hyp.idmap.text)                              \

> >>       VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;       \

> >> -     VMLINUX_SYMBOL(__hyp_text_start) = .;           \

> >> +     VMLINUX_SYMBOL(__kvm_hyp_code_start) = .;       \

> >>       *(.hyp.text)                                    \

> >> -     VMLINUX_SYMBOL(__hyp_text_end) = .;

> >> +     VMLINUX_SYMBOL(__kvm_hyp_code_end) = .;

> >

> > why this rename?

> >

> 

> I already got rid of it based on Marc's feedback. The only reason was

> to align between ARM and arm64, but he is already doing the same in

> the opposite direction


ah, now I understand what Marc was referring to in his comment, thanks.

-Christoffer
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diff mbox

Patch

diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 194c91b610ff..484ffdf7c70b 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -99,6 +99,8 @@  extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
 extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
 
 extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
+
+extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
 #endif
 
 #endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 405aa1883307..412b363f79e9 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -30,6 +30,8 @@ 
 #define HYP_PAGE_OFFSET		PAGE_OFFSET
 #define KERN_TO_HYP(kva)	(kva)
 
+#define kvm_ksym_ref(kva)	(kva)
+
 /*
  * Our virtual mapping for the boot-time MMU-enable code. Must be
  * shared across all the page-tables. Conveniently, we use the vectors
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index e06fd299de08..014b542ea658 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -427,7 +427,7 @@  static void update_vttbr(struct kvm *kvm)
 		 * shareable domain to make sure all data structures are
 		 * clean.
 		 */
-		kvm_call_hyp(__kvm_flush_vm_context);
+		kvm_call_hyp(kvm_ksym_ref(__kvm_flush_vm_context));
 	}
 
 	kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);
@@ -600,7 +600,7 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		__kvm_guest_enter();
 		vcpu->mode = IN_GUEST_MODE;
 
-		ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);
+		ret = kvm_call_hyp(kvm_ksym_ref(__kvm_vcpu_run), vcpu);
 
 		vcpu->mode = OUTSIDE_GUEST_MODE;
 		/*
@@ -969,7 +969,7 @@  static void cpu_init_hyp_mode(void *dummy)
 	pgd_ptr = kvm_mmu_get_httbr();
 	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);
 	hyp_stack_ptr = stack_page + PAGE_SIZE;
-	vector_ptr = (unsigned long)__kvm_hyp_vector;
+	vector_ptr = (unsigned long)kvm_ksym_ref(__kvm_hyp_vector);
 
 	__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
 
@@ -1061,7 +1061,8 @@  static int init_hyp_mode(void)
 	/*
 	 * Map the Hyp-code called directly from the host
 	 */
-	err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);
+	err = create_hyp_mappings(kvm_ksym_ref(__kvm_hyp_code_start),
+				  kvm_ksym_ref(__kvm_hyp_code_end));
 	if (err) {
 		kvm_err("Cannot map world-switch code\n");
 		goto out_free_mappings;
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 7dace909d5cf..7c448b943e3a 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -31,8 +31,6 @@ 
 
 #include "trace.h"
 
-extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];
-
 static pgd_t *boot_hyp_pgd;
 static pgd_t *hyp_pgd;
 static pgd_t *merged_hyp_pgd;
@@ -63,7 +61,7 @@  static bool memslot_is_logging(struct kvm_memory_slot *memslot)
  */
 void kvm_flush_remote_tlbs(struct kvm *kvm)
 {
-	kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
+	kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid), kvm);
 }
 
 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
@@ -75,7 +73,7 @@  static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
 	 * anything there.
 	 */
 	if (kvm)
-		kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
+		kvm_call_hyp(kvm_ksym_ref(__kvm_tlb_flush_vmid_ipa), kvm, ipa);
 }
 
 /*
@@ -1647,9 +1645,9 @@  int kvm_mmu_init(void)
 {
 	int err;
 
-	hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
-	hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
-	hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
+	hyp_idmap_start = kvm_virt_to_phys(&__hyp_idmap_text_start);
+	hyp_idmap_end = kvm_virt_to_phys(&__hyp_idmap_text_end);
+	hyp_idmap_vector = kvm_virt_to_phys(&__kvm_hyp_init);
 
 	/*
 	 * We rely on the linker script to ensure at build time that the HYP
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 5e377101f919..830402f847e0 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -105,24 +105,27 @@ 
 #ifndef __ASSEMBLY__
 struct kvm;
 struct kvm_vcpu;
+struct kvm_ksym;
 
 extern char __kvm_hyp_init[];
 extern char __kvm_hyp_init_end[];
 
-extern char __kvm_hyp_vector[];
+extern struct kvm_ksym __kvm_hyp_vector;
 
-#define	__kvm_hyp_code_start	__hyp_text_start
-#define	__kvm_hyp_code_end	__hyp_text_end
+extern struct kvm_ksym __kvm_hyp_code_start;
+extern struct kvm_ksym __kvm_hyp_code_end;
 
-extern void __kvm_flush_vm_context(void);
-extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
-extern void __kvm_tlb_flush_vmid(struct kvm *kvm);
+extern struct kvm_ksym __kvm_flush_vm_context;
+extern struct kvm_ksym __kvm_tlb_flush_vmid_ipa;
+extern struct kvm_ksym __kvm_tlb_flush_vmid;
 
-extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
+extern struct kvm_ksym __kvm_vcpu_run;
 
-extern u64 __vgic_v3_get_ich_vtr_el2(void);
+extern struct kvm_ksym __hyp_idmap_text_start, __hyp_idmap_text_end;
 
-extern u32 __kvm_get_mdcr_el2(void);
+extern struct kvm_ksym __vgic_v3_get_ich_vtr_el2;
+
+extern struct kvm_ksym __kvm_get_mdcr_el2;
 
 #endif
 
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 61505676d085..0899026a2821 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -73,6 +73,8 @@ 
 
 #define KERN_TO_HYP(kva)	((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)
 
+#define kvm_ksym_ref(sym)	((void *)&sym - KIMAGE_VADDR + PAGE_OFFSET)
+
 /*
  * We currently only support a 40bit IPA.
  */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 7a5df5252dd7..215ad4649dd7 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -50,10 +50,6 @@  static inline bool is_hyp_mode_mismatched(void)
 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
 }
 
-/* The section containing the hypervisor text */
-extern char __hyp_text_start[];
-extern char __hyp_text_end[];
-
 #endif /* __ASSEMBLY__ */
 
 #endif /* ! __ASM__VIRT_H */
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 363c2f529951..f935f082188d 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -35,9 +35,9 @@  jiffies = jiffies_64;
 	VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;	\
 	*(.hyp.idmap.text)				\
 	VMLINUX_SYMBOL(__hyp_idmap_text_end) = .;	\
-	VMLINUX_SYMBOL(__hyp_text_start) = .;		\
+	VMLINUX_SYMBOL(__kvm_hyp_code_start) = .;	\
 	*(.hyp.text)					\
-	VMLINUX_SYMBOL(__hyp_text_end) = .;
+	VMLINUX_SYMBOL(__kvm_hyp_code_end) = .;
 
 #define IDMAP_TEXT					\
 	. = ALIGN(SZ_4K);				\
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 47e5f0feaee8..99e5a403af4e 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -24,6 +24,7 @@ 
 #include <asm/kvm_asm.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_emulate.h>
+#include <asm/kvm_mmu.h>
 
 #include "trace.h"
 
@@ -72,7 +73,8 @@  static void restore_guest_debug_regs(struct kvm_vcpu *vcpu)
 
 void kvm_arm_init_debug(void)
 {
-	__this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2));
+	__this_cpu_write(mdcr_el2,
+			 kvm_call_hyp(kvm_ksym_ref(__kvm_get_mdcr_el2)));
 }
 
 /**
diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
index 487d6357b7e7..58f5a6521307 100644
--- a/virt/kvm/arm/vgic-v3.c
+++ b/virt/kvm/arm/vgic-v3.c
@@ -247,7 +247,7 @@  int vgic_v3_probe(struct device_node *vgic_node,
 		goto out;
 	}
 
-	ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
+	ich_vtr_el2 = kvm_call_hyp(kvm_ksym_ref(__vgic_v3_get_ich_vtr_el2));
 
 	/*
 	 * The ListRegs field is 5 bits, but there is a architectural