diff mbox series

[Xen-devel,v4,11/19] xen/arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support

Message ID 20180223164753.27311-12-julien.grall@arm.com
State Superseded
Headers show
Series xen/arm: PSCI 1.1 and SMCCC-1.1 support and XSA-254 variant 2 update | expand

Commit Message

Julien Grall Feb. 23, 2018, 4:47 p.m. UTC
Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v4:
        - Re-order saving/restoring registers in
          __smccc_workaround_1_smc_start

    Changes in v3:
        - Add the missing call to smc #0.

    Changes in v2:
        - Patch added
---
 xen/arch/arm/arm64/bpi.S    | 13 +++++++++++++
 xen/arch/arm/cpuerrata.c    | 32 +++++++++++++++++++++++++++++++-
 xen/include/asm-arm/smccc.h |  1 +
 3 files changed, 45 insertions(+), 1 deletion(-)

Comments

Volodymyr Babchuk Feb. 23, 2018, 6:18 p.m. UTC | #1
Hi Julien,

On 23.02.18 18:47, Julien Grall wrote:
> Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> 
> ---
>      Changes in v4:
>          - Re-order saving/restoring registers in
>            __smccc_workaround_1_smc_start
Looks like you missed to run --autosquash, so the real change is in the 
next patch.
> 
>      Changes in v3:
>          - Add the missing call to smc #0.
> 
>      Changes in v2:
>          - Patch added
> ---
>   xen/arch/arm/arm64/bpi.S    | 13 +++++++++++++
>   xen/arch/arm/cpuerrata.c    | 32 +++++++++++++++++++++++++++++++-
>   xen/include/asm-arm/smccc.h |  1 +
>   3 files changed, 45 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/arm64/bpi.S b/xen/arch/arm/arm64/bpi.S
> index 4b7f1dc21f..981fb83a88 100644
> --- a/xen/arch/arm/arm64/bpi.S
> +++ b/xen/arch/arm/arm64/bpi.S
> @@ -16,6 +16,8 @@
>    * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>    */
>   
> +#include <asm/smccc.h>
> +
>   .macro ventry target
>       .rept 31
>       nop
> @@ -81,6 +83,17 @@ ENTRY(__psci_hyp_bp_inval_start)
>       add     sp, sp, #(8 * 18)
>   ENTRY(__psci_hyp_bp_inval_end)
>   
> +ENTRY(__smccc_workaround_1_smc_start)
> +    sub     sp, sp, #(8 * 4)
> +    stp     x2, x3, [sp, #(8 * 0)]
> +    stp     x0, x1, [sp, #(8 * 2)]
> +    mov     w0, #ARM_SMCCC_ARCH_WORKAROUND_1_FID
> +    smc     #0
> +    ldp     x2, x3, [sp, #(8 * 0)]
> +    ldp     x0, x1, [sp, #(8 * 2)]
> +    add     sp, sp, #(8 * 4)
> +ENTRY(__smccc_workaround_1_smc_end)
> +
>   /*
>    * Local variables:
>    * mode: ASM
> diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
> index 8d5f8d372a..dec9074422 100644
> --- a/xen/arch/arm/cpuerrata.c
> +++ b/xen/arch/arm/cpuerrata.c
> @@ -147,6 +147,34 @@ install_bp_hardening_vec(const struct arm_cpu_capabilities *entry,
>       return ret;
>   }
>   
> +extern char __smccc_workaround_1_smc_start[], __smccc_workaround_1_smc_end[];
> +
> +static bool
> +check_smccc_arch_workaround_1(const struct arm_cpu_capabilities *entry)
> +{
> +    struct arm_smccc_res res;
> +
> +    /*
> +     * Enable callbacks are called on every CPU based on the
> +     * capabilities. So double-check whether the CPU matches the
> +     * entry.
> +     */
> +    if ( !entry->matches(entry) )
> +        return false;
> +
> +    if ( smccc_ver < SMCCC_VERSION(1, 1) )
> +        return false;
> +
> +    arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FID,
> +                      ARM_SMCCC_ARCH_WORKAROUND_1_FID, &res);
> +    if ( res.a0 != ARM_SMCCC_SUCCESS )
> +        return false;
> +
> +    return install_bp_hardening_vec(entry,__smccc_workaround_1_smc_start,
> +                                    __smccc_workaround_1_smc_end,
> +                                    "call ARM_SMCCC_ARCH_WORKAROUND_1");
> +}
> +
>   extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[];
>   
>   static int enable_psci_bp_hardening(void *data)
> @@ -154,12 +182,14 @@ static int enable_psci_bp_hardening(void *data)
>       bool ret = true;
>       static bool warned = false;
>   
> +    if ( check_smccc_arch_workaround_1(data) )
> +        return 0;
>       /*
>        * The mitigation is using PSCI version function to invalidate the
>        * branch predictor. This function is only available with PSCI 0.2
>        * and later.
>        */
> -    if ( psci_ver >= PSCI_VERSION(0, 2) )
> +    else if ( psci_ver >= PSCI_VERSION(0, 2) )
>           ret = install_bp_hardening_vec(data, __psci_hyp_bp_inval_start,
>                                          __psci_hyp_bp_inval_end,
>                                          "call PSCI get version");
> diff --git a/xen/include/asm-arm/smccc.h b/xen/include/asm-arm/smccc.h
> index 154772b728..8342cc33fe 100644
> --- a/xen/include/asm-arm/smccc.h
> +++ b/xen/include/asm-arm/smccc.h
> @@ -261,6 +261,7 @@ struct arm_smccc_res {
>   /* SMCCC error codes */
>   #define ARM_SMCCC_ERR_UNKNOWN_FUNCTION  (-1)
>   #define ARM_SMCCC_NOT_SUPPORTED         (-1)
> +#define ARM_SMCCC_SUCCESS               (0)
>   
>   /* SMCCC function identifier range which is reserved for existing APIs */
>   #define ARM_SMCCC_RESERVED_RANGE_START  0x0
>
Julien Grall Feb. 23, 2018, 6:53 p.m. UTC | #2
On 23/02/18 18:18, Volodymyr Babchuk wrote:
> Hi Julien,

Hi Volodymyr,

> On 23.02.18 18:47, Julien Grall wrote:
>> Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>>
>> ---
>>      Changes in v4:
>>          - Re-order saving/restoring registers in
>>            __smccc_workaround_1_smc_start
> Looks like you missed to run --autosquash, so the real change is in the 
> next patch.

Whoops yes. Thank you for spotting it. I will resend the version.

Cheers,

>>
>>      Changes in v3:
>>          - Add the missing call to smc #0.
>>
>>      Changes in v2:
>>          - Patch added
>> ---
>>   xen/arch/arm/arm64/bpi.S    | 13 +++++++++++++
>>   xen/arch/arm/cpuerrata.c    | 32 +++++++++++++++++++++++++++++++-
>>   xen/include/asm-arm/smccc.h |  1 +
>>   3 files changed, 45 insertions(+), 1 deletion(-)
>>
>> diff --git a/xen/arch/arm/arm64/bpi.S b/xen/arch/arm/arm64/bpi.S
>> index 4b7f1dc21f..981fb83a88 100644
>> --- a/xen/arch/arm/arm64/bpi.S
>> +++ b/xen/arch/arm/arm64/bpi.S
>> @@ -16,6 +16,8 @@
>>    * along with this program.  If not, see 
>> <http://www.gnu.org/licenses/>.
>>    */
>> +#include <asm/smccc.h>
>> +
>>   .macro ventry target
>>       .rept 31
>>       nop
>> @@ -81,6 +83,17 @@ ENTRY(__psci_hyp_bp_inval_start)
>>       add     sp, sp, #(8 * 18)
>>   ENTRY(__psci_hyp_bp_inval_end)
>> +ENTRY(__smccc_workaround_1_smc_start)
>> +    sub     sp, sp, #(8 * 4)
>> +    stp     x2, x3, [sp, #(8 * 0)]
>> +    stp     x0, x1, [sp, #(8 * 2)]
>> +    mov     w0, #ARM_SMCCC_ARCH_WORKAROUND_1_FID
>> +    smc     #0
>> +    ldp     x2, x3, [sp, #(8 * 0)]
>> +    ldp     x0, x1, [sp, #(8 * 2)]
>> +    add     sp, sp, #(8 * 4)
>> +ENTRY(__smccc_workaround_1_smc_end)
>> +
>>   /*
>>    * Local variables:
>>    * mode: ASM
>> diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
>> index 8d5f8d372a..dec9074422 100644
>> --- a/xen/arch/arm/cpuerrata.c
>> +++ b/xen/arch/arm/cpuerrata.c
>> @@ -147,6 +147,34 @@ install_bp_hardening_vec(const struct 
>> arm_cpu_capabilities *entry,
>>       return ret;
>>   }
>> +extern char __smccc_workaround_1_smc_start[], 
>> __smccc_workaround_1_smc_end[];
>> +
>> +static bool
>> +check_smccc_arch_workaround_1(const struct arm_cpu_capabilities *entry)
>> +{
>> +    struct arm_smccc_res res;
>> +
>> +    /*
>> +     * Enable callbacks are called on every CPU based on the
>> +     * capabilities. So double-check whether the CPU matches the
>> +     * entry.
>> +     */
>> +    if ( !entry->matches(entry) )
>> +        return false;
>> +
>> +    if ( smccc_ver < SMCCC_VERSION(1, 1) )
>> +        return false;
>> +
>> +    arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FID,
>> +                      ARM_SMCCC_ARCH_WORKAROUND_1_FID, &res);
>> +    if ( res.a0 != ARM_SMCCC_SUCCESS )
>> +        return false;
>> +
>> +    return 
>> install_bp_hardening_vec(entry,__smccc_workaround_1_smc_start,
>> +                                    __smccc_workaround_1_smc_end,
>> +                                    "call ARM_SMCCC_ARCH_WORKAROUND_1");
>> +}
>> +
>>   extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[];
>>   static int enable_psci_bp_hardening(void *data)
>> @@ -154,12 +182,14 @@ static int enable_psci_bp_hardening(void *data)
>>       bool ret = true;
>>       static bool warned = false;
>> +    if ( check_smccc_arch_workaround_1(data) )
>> +        return 0;
>>       /*
>>        * The mitigation is using PSCI version function to invalidate the
>>        * branch predictor. This function is only available with PSCI 0.2
>>        * and later.
>>        */
>> -    if ( psci_ver >= PSCI_VERSION(0, 2) )
>> +    else if ( psci_ver >= PSCI_VERSION(0, 2) )
>>           ret = install_bp_hardening_vec(data, __psci_hyp_bp_inval_start,
>>                                          __psci_hyp_bp_inval_end,
>>                                          "call PSCI get version");
>> diff --git a/xen/include/asm-arm/smccc.h b/xen/include/asm-arm/smccc.h
>> index 154772b728..8342cc33fe 100644
>> --- a/xen/include/asm-arm/smccc.h
>> +++ b/xen/include/asm-arm/smccc.h
>> @@ -261,6 +261,7 @@ struct arm_smccc_res {
>>   /* SMCCC error codes */
>>   #define ARM_SMCCC_ERR_UNKNOWN_FUNCTION  (-1)
>>   #define ARM_SMCCC_NOT_SUPPORTED         (-1)
>> +#define ARM_SMCCC_SUCCESS               (0)
>>   /* SMCCC function identifier range which is reserved for existing 
>> APIs */
>>   #define ARM_SMCCC_RESERVED_RANGE_START  0x0
>>
>
diff mbox series

Patch

diff --git a/xen/arch/arm/arm64/bpi.S b/xen/arch/arm/arm64/bpi.S
index 4b7f1dc21f..981fb83a88 100644
--- a/xen/arch/arm/arm64/bpi.S
+++ b/xen/arch/arm/arm64/bpi.S
@@ -16,6 +16,8 @@ 
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <asm/smccc.h>
+
 .macro ventry target
     .rept 31
     nop
@@ -81,6 +83,17 @@  ENTRY(__psci_hyp_bp_inval_start)
     add     sp, sp, #(8 * 18)
 ENTRY(__psci_hyp_bp_inval_end)
 
+ENTRY(__smccc_workaround_1_smc_start)
+    sub     sp, sp, #(8 * 4)
+    stp     x2, x3, [sp, #(8 * 0)]
+    stp     x0, x1, [sp, #(8 * 2)]
+    mov     w0, #ARM_SMCCC_ARCH_WORKAROUND_1_FID
+    smc     #0
+    ldp     x2, x3, [sp, #(8 * 0)]
+    ldp     x0, x1, [sp, #(8 * 2)]
+    add     sp, sp, #(8 * 4)
+ENTRY(__smccc_workaround_1_smc_end)
+
 /*
  * Local variables:
  * mode: ASM
diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
index 8d5f8d372a..dec9074422 100644
--- a/xen/arch/arm/cpuerrata.c
+++ b/xen/arch/arm/cpuerrata.c
@@ -147,6 +147,34 @@  install_bp_hardening_vec(const struct arm_cpu_capabilities *entry,
     return ret;
 }
 
+extern char __smccc_workaround_1_smc_start[], __smccc_workaround_1_smc_end[];
+
+static bool
+check_smccc_arch_workaround_1(const struct arm_cpu_capabilities *entry)
+{
+    struct arm_smccc_res res;
+
+    /*
+     * Enable callbacks are called on every CPU based on the
+     * capabilities. So double-check whether the CPU matches the
+     * entry.
+     */
+    if ( !entry->matches(entry) )
+        return false;
+
+    if ( smccc_ver < SMCCC_VERSION(1, 1) )
+        return false;
+
+    arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FID,
+                      ARM_SMCCC_ARCH_WORKAROUND_1_FID, &res);
+    if ( res.a0 != ARM_SMCCC_SUCCESS )
+        return false;
+
+    return install_bp_hardening_vec(entry,__smccc_workaround_1_smc_start,
+                                    __smccc_workaround_1_smc_end,
+                                    "call ARM_SMCCC_ARCH_WORKAROUND_1");
+}
+
 extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[];
 
 static int enable_psci_bp_hardening(void *data)
@@ -154,12 +182,14 @@  static int enable_psci_bp_hardening(void *data)
     bool ret = true;
     static bool warned = false;
 
+    if ( check_smccc_arch_workaround_1(data) )
+        return 0;
     /*
      * The mitigation is using PSCI version function to invalidate the
      * branch predictor. This function is only available with PSCI 0.2
      * and later.
      */
-    if ( psci_ver >= PSCI_VERSION(0, 2) )
+    else if ( psci_ver >= PSCI_VERSION(0, 2) )
         ret = install_bp_hardening_vec(data, __psci_hyp_bp_inval_start,
                                        __psci_hyp_bp_inval_end,
                                        "call PSCI get version");
diff --git a/xen/include/asm-arm/smccc.h b/xen/include/asm-arm/smccc.h
index 154772b728..8342cc33fe 100644
--- a/xen/include/asm-arm/smccc.h
+++ b/xen/include/asm-arm/smccc.h
@@ -261,6 +261,7 @@  struct arm_smccc_res {
 /* SMCCC error codes */
 #define ARM_SMCCC_ERR_UNKNOWN_FUNCTION  (-1)
 #define ARM_SMCCC_NOT_SUPPORTED         (-1)
+#define ARM_SMCCC_SUCCESS               (0)
 
 /* SMCCC function identifier range which is reserved for existing APIs */
 #define ARM_SMCCC_RESERVED_RANGE_START  0x0