KVM: VMX: restore vmx_vmexit alignment

[PATCH] KVM: VMX: restore vmx_vmexit alignment

Posted by Jon Kohler 2 years, 8 months ago

Commit 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") changed
vmx_vmexit from SYM_FUNC_START to SYM_INNER_LABEL, accidentally
removing 16 byte alignment as SYM_FUNC_START uses SYM_A_ALIGN and
SYM_INNER_LABEL does not. Josh mentioned [1] this was unintentional.

Fix by changing to SYM_INNER_LABEL_ALIGN instead.

[1] https://lore.kernel.org/lkml/Y3adkSe%2FJ70PqUyt@p183

Fixes: 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()")
Signed-off-by: Jon Kohler <jon@nutanix.com>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
CC: Josh Poimboeuf <jpoimboe@kernel.org>
---
 arch/x86/kvm/vmx/vmenter.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 631fd7da2bc3..07e927d4d099 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -187,7 +187,7 @@ SYM_FUNC_START(__vmx_vcpu_run)
 	_ASM_EXTABLE(.Lvmresume, .Lfixup)
 	_ASM_EXTABLE(.Lvmlaunch, .Lfixup)
 
-SYM_INNER_LABEL(vmx_vmexit, SYM_L_GLOBAL)
+SYM_INNER_LABEL_ALIGN(vmx_vmexit, SYM_L_GLOBAL)
 
 	/* Restore unwind state from before the VMRESUME/VMLAUNCH. */
 	UNWIND_HINT_RESTORE
-- 
2.30.1 (Apple Git-130)

Re: [PATCH] KVM: VMX: restore vmx_vmexit alignment

Posted by Sean Christopherson 2 years, 8 months ago

On Wed, 31 May 2023 11:58:21 -0400, Jon Kohler wrote:
> Commit 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") changed
> vmx_vmexit from SYM_FUNC_START to SYM_INNER_LABEL, accidentally
> removing 16 byte alignment as SYM_FUNC_START uses SYM_A_ALIGN and
> SYM_INNER_LABEL does not. Josh mentioned [1] this was unintentional.
> 
> Fix by changing to SYM_INNER_LABEL_ALIGN instead.
> 
> [...]

Applied to kvm-x86 vmx, thanks!

[1/1] KVM: VMX: restore vmx_vmexit alignment
      https://github.com/kvm-x86/linux/commit/331f22976816

--
https://github.com/kvm-x86/linux/tree/next
https://github.com/kvm-x86/linux/tree/fixes

Re: [PATCH] KVM: VMX: restore vmx_vmexit alignment

Posted by Josh Poimboeuf 2 years, 8 months ago

On Wed, May 31, 2023 at 11:58:21AM -0400, Jon Kohler wrote:
> Commit 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") changed
> vmx_vmexit from SYM_FUNC_START to SYM_INNER_LABEL, accidentally
> removing 16 byte alignment as SYM_FUNC_START uses SYM_A_ALIGN and
> SYM_INNER_LABEL does not. Josh mentioned [1] this was unintentional.
> 
> Fix by changing to SYM_INNER_LABEL_ALIGN instead.
> 
> [1] https://lore.kernel.org/lkml/Y3adkSe%2FJ70PqUyt@p183
> 
> Fixes: 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()")
> Signed-off-by: Jon Kohler <jon@nutanix.com>
> Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
> CC: Josh Poimboeuf <jpoimboe@kernel.org>

Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>

-- 
Josh

Re: [PATCH] KVM: VMX: restore vmx_vmexit alignment

Posted by Jim Mattson 2 years, 8 months ago

On Wed, May 31, 2023 at 8:59 AM Jon Kohler <jon@nutanix.com> wrote:
>
> Commit 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") changed
> vmx_vmexit from SYM_FUNC_START to SYM_INNER_LABEL, accidentally
> removing 16 byte alignment as SYM_FUNC_START uses SYM_A_ALIGN and
> SYM_INNER_LABEL does not. Josh mentioned [1] this was unintentional.
>
> Fix by changing to SYM_INNER_LABEL_ALIGN instead.
>
> [1] https://lore.kernel.org/lkml/Y3adkSe%2FJ70PqUyt@p183
>
> Fixes: 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()")
> Signed-off-by: Jon Kohler <jon@nutanix.com>
> Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
> CC: Josh Poimboeuf <jpoimboe@kernel.org>

Reviewed-by: Jim Mattson <jmattson@google.com>