diff mbox series

[v2,4/9] x86/hyperv: Parse the ACPI wakeup mailbox

Message ID 20240823232327.2408869-5-yunhong.jiang@linux.intel.com
State New
Headers show
Series x86/hyperv: Support wakeup mailbox for VTL2 TDX guest | expand

Commit Message

Yunhong Jiang Aug. 23, 2024, 11:23 p.m. UTC
Parse the wakeup mailbox VTL2 TDX guest. Put it to the guest_late_init, so
that it will be invoked before hyperv_init() where the mailbox address is
checked.

Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
---
 arch/x86/include/asm/mshyperv.h | 3 +++
 arch/x86/kernel/cpu/mshyperv.c  | 2 ++
 drivers/hv/hv_common.c          | 8 ++++++++
 3 files changed, 13 insertions(+)

Comments

Michael Kelley Sept. 2, 2024, 3:35 a.m. UTC | #1
From: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> 
> Parse the wakeup mailbox VTL2 TDX guest. Put it to the guest_late_init, so
> that it will be invoked before hyperv_init() where the mailbox address is
> checked.

Could you elaborate on the choice to set the wakeup_mailbox_address
in ms_hyperv_late_init()? The code in hv_common.c is intended to be
code that is architecture neutral (see the comment at the top of the module),
so it's a red flag to see #ifdef CONFIG_X86_64. Couldn't the
wakeup_mailbox_address be set in the x86 version of hyperv_init()
before it is needed?

> 
> Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> ---
>  arch/x86/include/asm/mshyperv.h | 3 +++
>  arch/x86/kernel/cpu/mshyperv.c  | 2 ++
>  drivers/hv/hv_common.c          | 8 ++++++++
>  3 files changed, 13 insertions(+)
> 
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index 390c4d13956d..5178b96c7fc9 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -10,6 +10,7 @@
>  #include <asm/nospec-branch.h>
>  #include <asm/paravirt.h>
>  #include <asm/mshyperv.h>
> +#include <asm/madt_wakeup.h>
> 
>  /*
>   * Hyper-V always provides a single IO-APIC at this MMIO address.
> @@ -49,6 +50,8 @@ extern u64 hv_current_partition_id;
> 
>  extern union hv_ghcb * __percpu *hv_ghcb_pg;
> 
> +extern u64 wakeup_mailbox_addr;
> +
>  bool hv_isolation_type_snp(void);
>  bool hv_isolation_type_tdx(void);
>  u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 3d4237f27569..f6b727b4bd0b 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -43,6 +43,8 @@ struct ms_hyperv_info ms_hyperv;
>  bool hyperv_paravisor_present __ro_after_init;
>  EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
> 
> +u64 wakeup_mailbox_addr;

This value duplicates acpi_mp_wake_mailbox_paddr in
madt_wakeup.c. It looks like the duplicate value is used
for two things:

1) In hv_is_private_mmio_tdx() to control the encrypted
vs. decrypted mapping (Patch 5 of this series)

2) As a boolean in hv_vtl_early_init() to avoid overwriting
the wakeup_secondary_cpu_64 value when
dtb_parse_mp_wake() has set it to acpi_wakeup_cpu().
(Patch 9 of this series).

Having a duplicate value is messy, and I'm wondering if
it can be avoided. For (1), hv_private_mmio_tdx() could call
into a function added to madt_wakeup.c to make the
check.  For (2), the check should probably be based on
hv_isolation_type_tdx() instead of whether the wakeup
mailbox address is set.  I'll note that Patch 5 of this series
is using hv_isolation_type_tdx(), so there's a bit of an
inconsistency in testing the wakeup_mailbox_addr in
Patch 9.

This is just a suggestion, as I haven't worked out all
the details. If you think it ends up being messier than
the duplicate value, then I'm OK with it.

Michael

> +
>  #if IS_ENABLED(CONFIG_HYPERV)
>  static inline unsigned int hv_get_nested_msr(unsigned int reg)
>  {
> diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> index 9c452bfbd571..14b005b6270f 100644
> --- a/drivers/hv/hv_common.c
> +++ b/drivers/hv/hv_common.c
> @@ -365,6 +365,14 @@ void __init ms_hyperv_late_init(void)
>  	u8 *randomdata;
>  	u32 length, i;
> 
> +	/*
> +	 * Parse the ACPI wakeup structure information from device tree.
> +	 * Currently VTL2 TDX guest only.
> +	 */
> +#ifdef CONFIG_X86_64
> +	wakeup_mailbox_addr = dtb_parse_mp_wake();
> +#endif
> +
>  	/*
>  	 * Seed the Linux random number generator with entropy provided by
>  	 * the Hyper-V host in ACPI table OEM0.
> --
> 2.25.1
>
Yunhong Jiang Sept. 3, 2024, 8:19 p.m. UTC | #2
On Mon, Sep 02, 2024 at 03:35:13AM +0000, Michael Kelley wrote:
> From: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > 
> > Parse the wakeup mailbox VTL2 TDX guest. Put it to the guest_late_init, so
> > that it will be invoked before hyperv_init() where the mailbox address is
> > checked.
> 
> Could you elaborate on the choice to set the wakeup_mailbox_address
> in ms_hyperv_late_init()? The code in hv_common.c is intended to be
> code that is architecture neutral (see the comment at the top of the module),
> so it's a red flag to see #ifdef CONFIG_X86_64. Couldn't the
> wakeup_mailbox_address be set in the x86 version of hyperv_init()
> before it is needed?

Sure, will try to put it in hyperv_init() before it's needed.
> 
> > 
> > Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > ---
> >  arch/x86/include/asm/mshyperv.h | 3 +++
> >  arch/x86/kernel/cpu/mshyperv.c  | 2 ++
> >  drivers/hv/hv_common.c          | 8 ++++++++
> >  3 files changed, 13 insertions(+)
> > 
> > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> > index 390c4d13956d..5178b96c7fc9 100644
> > --- a/arch/x86/include/asm/mshyperv.h
> > +++ b/arch/x86/include/asm/mshyperv.h
> > @@ -10,6 +10,7 @@
> >  #include <asm/nospec-branch.h>
> >  #include <asm/paravirt.h>
> >  #include <asm/mshyperv.h>
> > +#include <asm/madt_wakeup.h>
> > 
> >  /*
> >   * Hyper-V always provides a single IO-APIC at this MMIO address.
> > @@ -49,6 +50,8 @@ extern u64 hv_current_partition_id;
> > 
> >  extern union hv_ghcb * __percpu *hv_ghcb_pg;
> > 
> > +extern u64 wakeup_mailbox_addr;
> > +
> >  bool hv_isolation_type_snp(void);
> >  bool hv_isolation_type_tdx(void);
> >  u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
> > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> > index 3d4237f27569..f6b727b4bd0b 100644
> > --- a/arch/x86/kernel/cpu/mshyperv.c
> > +++ b/arch/x86/kernel/cpu/mshyperv.c
> > @@ -43,6 +43,8 @@ struct ms_hyperv_info ms_hyperv;
> >  bool hyperv_paravisor_present __ro_after_init;
> >  EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
> > 
> > +u64 wakeup_mailbox_addr;
> 
> This value duplicates acpi_mp_wake_mailbox_paddr in
> madt_wakeup.c. It looks like the duplicate value is used
> for two things:
> 
> 1) In hv_is_private_mmio_tdx() to control the encrypted
> vs. decrypted mapping (Patch 5 of this series)
> 
> 2) As a boolean in hv_vtl_early_init() to avoid overwriting
> the wakeup_secondary_cpu_64 value when
> dtb_parse_mp_wake() has set it to acpi_wakeup_cpu().
> (Patch 9 of this series).
> 
> Having a duplicate value is messy, and I'm wondering if
> it can be avoided. For (1), hv_private_mmio_tdx() could call
> into a function added to madt_wakeup.c to make the
> check.  For (2), the check should probably be based on
> hv_isolation_type_tdx() instead of whether the wakeup
> mailbox address is set.  I'll note that Patch 5 of this series
> is using hv_isolation_type_tdx(), so there's a bit of an
> inconsistency in testing the wakeup_mailbox_addr in
> Patch 9.

I think your comment includes two points, the duplicated variables and the
incosistency in the testing.

Thank you for pointing out the duplication of wakeup_mailbox_addr with
acpi_mp_wake_mailbox_paddr. I didn't realize it. Yes, such duplication should be
avoided and will fix it in next submission.

Agree the inconsistency in testing wakeup_mailbox_addr and
hv_isolation_type_tdx() is not good. IMHO, the wakeup_mailbox_addr (or the new
function you proposed) is better than hv_isolation_type_tdx(), since the
wakeup_mailbox_addr is more directly related.  But hv_vtl_init_platform()
happens before DT parse, thus I have to use the hv_isolation_type_tdx() in it. I
don't have a good idea on how to fix this.

Thanks
--jyh

> 
> This is just a suggestion, as I haven't worked out all
> the details. If you think it ends up being messier than
> the duplicate value, then I'm OK with it.
> 
> Michael
> 
> > +
> >  #if IS_ENABLED(CONFIG_HYPERV)
> >  static inline unsigned int hv_get_nested_msr(unsigned int reg)
> >  {
> > diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
> > index 9c452bfbd571..14b005b6270f 100644
> > --- a/drivers/hv/hv_common.c
> > +++ b/drivers/hv/hv_common.c
> > @@ -365,6 +365,14 @@ void __init ms_hyperv_late_init(void)
> >  	u8 *randomdata;
> >  	u32 length, i;
> > 
> > +	/*
> > +	 * Parse the ACPI wakeup structure information from device tree.
> > +	 * Currently VTL2 TDX guest only.
> > +	 */
> > +#ifdef CONFIG_X86_64
> > +	wakeup_mailbox_addr = dtb_parse_mp_wake();
> > +#endif
> > +
> >  	/*
> >  	 * Seed the Linux random number generator with entropy provided by
> >  	 * the Hyper-V host in ACPI table OEM0.
> > --
> > 2.25.1
> > 
>
Michael Kelley Sept. 4, 2024, 2:56 p.m. UTC | #3
From: Yunhong Jiang <yunhong.jiang@linux.intel.com> Sent: Tuesday, September 3, 2024 1:19 PM
> 
> On Mon, Sep 02, 2024 at 03:35:13AM +0000, Michael Kelley wrote:
> > From: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > >
> > > Parse the wakeup mailbox VTL2 TDX guest. Put it to the guest_late_init, so
> > > that it will be invoked before hyperv_init() where the mailbox address is
> > > checked.
> >
> > Could you elaborate on the choice to set the wakeup_mailbox_address
> > in ms_hyperv_late_init()? The code in hv_common.c is intended to be
> > code that is architecture neutral (see the comment at the top of the module),
> > so it's a red flag to see #ifdef CONFIG_X86_64. Couldn't the
> > wakeup_mailbox_address be set in the x86 version of hyperv_init()
> > before it is needed?
> 
> Sure, will try to put it in hyperv_init() before it's needed.
> >
> > >
> > > Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > > ---
> > >  arch/x86/include/asm/mshyperv.h | 3 +++
> > >  arch/x86/kernel/cpu/mshyperv.c  | 2 ++
> > >  drivers/hv/hv_common.c          | 8 ++++++++
> > >  3 files changed, 13 insertions(+)
> > >
> > > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> > > index 390c4d13956d..5178b96c7fc9 100644
> > > --- a/arch/x86/include/asm/mshyperv.h
> > > +++ b/arch/x86/include/asm/mshyperv.h
> > > @@ -10,6 +10,7 @@
> > >  #include <asm/nospec-branch.h>
> > >  #include <asm/paravirt.h>
> > >  #include <asm/mshyperv.h>
> > > +#include <asm/madt_wakeup.h>
> > >
> > >  /*
> > >   * Hyper-V always provides a single IO-APIC at this MMIO address.
> > > @@ -49,6 +50,8 @@ extern u64 hv_current_partition_id;
> > >
> > >  extern union hv_ghcb * __percpu *hv_ghcb_pg;
> > >
> > > +extern u64 wakeup_mailbox_addr;
> > > +
> > >  bool hv_isolation_type_snp(void);
> > >  bool hv_isolation_type_tdx(void);
> > >  u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
> > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> > > index 3d4237f27569..f6b727b4bd0b 100644
> > > --- a/arch/x86/kernel/cpu/mshyperv.c
> > > +++ b/arch/x86/kernel/cpu/mshyperv.c
> > > @@ -43,6 +43,8 @@ struct ms_hyperv_info ms_hyperv;
> > >  bool hyperv_paravisor_present __ro_after_init;
> > >  EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
> > >
> > > +u64 wakeup_mailbox_addr;
> >
> > This value duplicates acpi_mp_wake_mailbox_paddr in
> > madt_wakeup.c. It looks like the duplicate value is used
> > for two things:
> >
> > 1) In hv_is_private_mmio_tdx() to control the encrypted
> > vs. decrypted mapping (Patch 5 of this series)
> >
> > 2) As a boolean in hv_vtl_early_init() to avoid overwriting
> > the wakeup_secondary_cpu_64 value when
> > dtb_parse_mp_wake() has set it to acpi_wakeup_cpu().
> > (Patch 9 of this series).
> >
> > Having a duplicate value is messy, and I'm wondering if
> > it can be avoided. For (1), hv_private_mmio_tdx() could call
> > into a function added to madt_wakeup.c to make the
> > check.  For (2), the check should probably be based on
> > hv_isolation_type_tdx() instead of whether the wakeup
> > mailbox address is set.  I'll note that Patch 5 of this series
> > is using hv_isolation_type_tdx(), so there's a bit of an
> > inconsistency in testing the wakeup_mailbox_addr in
> > Patch 9.
> 
> I think your comment includes two points, the duplicated variables and the
> incosistency in the testing.
> 
> Thank you for pointing out the duplication of wakeup_mailbox_addr with
> acpi_mp_wake_mailbox_paddr. I didn't realize it. Yes, such duplication should be
> avoided and will fix it in next submission.
> 
> Agree the inconsistency in testing wakeup_mailbox_addr and
> hv_isolation_type_tdx() is not good. IMHO, the wakeup_mailbox_addr (or the new
> function you proposed) is better than hv_isolation_type_tdx(), since the
> wakeup_mailbox_addr is more directly related.  But hv_vtl_init_platform()
> happens before DT parse, thus I have to use the hv_isolation_type_tdx() in it. I
> don't have a good idea on how to fix this.
> 
> Thanks
> --jyh
> 

I don't think there's a requirement to set the "is_private_mmio"
function in hv_vtl_init_platform(). It just needs to be set before
acpi_wakeup_cpu() is called, which does the memremap() that will
invoke the "is_private_mmio" function to decide whether to map
as encrypted or decrypted.

So maybe setting the "is_private_mmio" function could be
done after dtb_parse_mp_wake() is called in its new location, and
you know you have a valid wake mailbox address? Again, I haven't
worked out all the details, so this approach might be just as messy,
but in a different way. Use your judgment ... :-)

Michael
Yunhong Jiang Sept. 4, 2024, 5:31 p.m. UTC | #4
On Wed, Sep 04, 2024 at 02:56:49PM +0000, Michael Kelley wrote:
> From: Yunhong Jiang <yunhong.jiang@linux.intel.com> Sent: Tuesday, September 3, 2024 1:19 PM
> > 
> > On Mon, Sep 02, 2024 at 03:35:13AM +0000, Michael Kelley wrote:
> > > From: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > > >
> > > > Parse the wakeup mailbox VTL2 TDX guest. Put it to the guest_late_init, so
> > > > that it will be invoked before hyperv_init() where the mailbox address is
> > > > checked.
> > >
> > > Could you elaborate on the choice to set the wakeup_mailbox_address
> > > in ms_hyperv_late_init()? The code in hv_common.c is intended to be
> > > code that is architecture neutral (see the comment at the top of the module),
> > > so it's a red flag to see #ifdef CONFIG_X86_64. Couldn't the
> > > wakeup_mailbox_address be set in the x86 version of hyperv_init()
> > > before it is needed?
> > 
> > Sure, will try to put it in hyperv_init() before it's needed.
> > >
> > > >
> > > > Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
> > > > ---
> > > >  arch/x86/include/asm/mshyperv.h | 3 +++
> > > >  arch/x86/kernel/cpu/mshyperv.c  | 2 ++
> > > >  drivers/hv/hv_common.c          | 8 ++++++++
> > > >  3 files changed, 13 insertions(+)
> > > >
> > > > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> > > > index 390c4d13956d..5178b96c7fc9 100644
> > > > --- a/arch/x86/include/asm/mshyperv.h
> > > > +++ b/arch/x86/include/asm/mshyperv.h
> > > > @@ -10,6 +10,7 @@
> > > >  #include <asm/nospec-branch.h>
> > > >  #include <asm/paravirt.h>
> > > >  #include <asm/mshyperv.h>
> > > > +#include <asm/madt_wakeup.h>
> > > >
> > > >  /*
> > > >   * Hyper-V always provides a single IO-APIC at this MMIO address.
> > > > @@ -49,6 +50,8 @@ extern u64 hv_current_partition_id;
> > > >
> > > >  extern union hv_ghcb * __percpu *hv_ghcb_pg;
> > > >
> > > > +extern u64 wakeup_mailbox_addr;
> > > > +
> > > >  bool hv_isolation_type_snp(void);
> > > >  bool hv_isolation_type_tdx(void);
> > > >  u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
> > > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> > > > index 3d4237f27569..f6b727b4bd0b 100644
> > > > --- a/arch/x86/kernel/cpu/mshyperv.c
> > > > +++ b/arch/x86/kernel/cpu/mshyperv.c
> > > > @@ -43,6 +43,8 @@ struct ms_hyperv_info ms_hyperv;
> > > >  bool hyperv_paravisor_present __ro_after_init;
> > > >  EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
> > > >
> > > > +u64 wakeup_mailbox_addr;
> > >
> > > This value duplicates acpi_mp_wake_mailbox_paddr in
> > > madt_wakeup.c. It looks like the duplicate value is used
> > > for two things:
> > >
> > > 1) In hv_is_private_mmio_tdx() to control the encrypted
> > > vs. decrypted mapping (Patch 5 of this series)
> > >
> > > 2) As a boolean in hv_vtl_early_init() to avoid overwriting
> > > the wakeup_secondary_cpu_64 value when
> > > dtb_parse_mp_wake() has set it to acpi_wakeup_cpu().
> > > (Patch 9 of this series).
> > >
> > > Having a duplicate value is messy, and I'm wondering if
> > > it can be avoided. For (1), hv_private_mmio_tdx() could call
> > > into a function added to madt_wakeup.c to make the
> > > check.  For (2), the check should probably be based on
> > > hv_isolation_type_tdx() instead of whether the wakeup
> > > mailbox address is set.  I'll note that Patch 5 of this series
> > > is using hv_isolation_type_tdx(), so there's a bit of an
> > > inconsistency in testing the wakeup_mailbox_addr in
> > > Patch 9.
> > 
> > I think your comment includes two points, the duplicated variables and the
> > incosistency in the testing.
> > 
> > Thank you for pointing out the duplication of wakeup_mailbox_addr with
> > acpi_mp_wake_mailbox_paddr. I didn't realize it. Yes, such duplication should be
> > avoided and will fix it in next submission.
> > 
> > Agree the inconsistency in testing wakeup_mailbox_addr and
> > hv_isolation_type_tdx() is not good. IMHO, the wakeup_mailbox_addr (or the new
> > function you proposed) is better than hv_isolation_type_tdx(), since the
> > wakeup_mailbox_addr is more directly related.  But hv_vtl_init_platform()
> > happens before DT parse, thus I have to use the hv_isolation_type_tdx() in it. I
> > don't have a good idea on how to fix this.
> > 
> > Thanks
> > --jyh
> > 
> 
> I don't think there's a requirement to set the "is_private_mmio"
> function in hv_vtl_init_platform(). It just needs to be set before
> acpi_wakeup_cpu() is called, which does the memremap() that will
> invoke the "is_private_mmio" function to decide whether to map
> as encrypted or decrypted.
> 
> So maybe setting the "is_private_mmio" function could be
> done after dtb_parse_mp_wake() is called in its new location, and
> you know you have a valid wake mailbox address? Again, I haven't
> worked out all the details, so this approach might be just as messy,
> but in a different way. Use your judgment ... :-)

Sorry that I didn't explain clearly. The testing in hv_vtl_init_platform() is
not only for the is_private_mmio, but also for the realmode_reserve(), which
happens before the DT parse.

BTW, I don't know why the trampoline_64.S is put into the real mode blob. I
don't find any specific requirement in the code, but I'm not sure if I missed
anything. If this dependency is removed, all the TDX guest will benefit.

Thank you
--jyh

> 
> Michael
diff mbox series

Patch

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 390c4d13956d..5178b96c7fc9 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -10,6 +10,7 @@ 
 #include <asm/nospec-branch.h>
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
+#include <asm/madt_wakeup.h>
 
 /*
  * Hyper-V always provides a single IO-APIC at this MMIO address.
@@ -49,6 +50,8 @@  extern u64 hv_current_partition_id;
 
 extern union hv_ghcb * __percpu *hv_ghcb_pg;
 
+extern u64 wakeup_mailbox_addr;
+
 bool hv_isolation_type_snp(void);
 bool hv_isolation_type_tdx(void);
 u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 3d4237f27569..f6b727b4bd0b 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -43,6 +43,8 @@  struct ms_hyperv_info ms_hyperv;
 bool hyperv_paravisor_present __ro_after_init;
 EXPORT_SYMBOL_GPL(hyperv_paravisor_present);
 
+u64 wakeup_mailbox_addr;
+
 #if IS_ENABLED(CONFIG_HYPERV)
 static inline unsigned int hv_get_nested_msr(unsigned int reg)
 {
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 9c452bfbd571..14b005b6270f 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -365,6 +365,14 @@  void __init ms_hyperv_late_init(void)
 	u8 *randomdata;
 	u32 length, i;
 
+	/*
+	 * Parse the ACPI wakeup structure information from device tree.
+	 * Currently VTL2 TDX guest only.
+	 */
+#ifdef CONFIG_X86_64
+	wakeup_mailbox_addr = dtb_parse_mp_wake();
+#endif
+
 	/*
 	 * Seed the Linux random number generator with entropy provided by
 	 * the Hyper-V host in ACPI table OEM0.