Hi all,

Today's linux-next merge of the kvm-x86 tree got a conflict in:

  arch/x86/kvm/vmx/vmx.c

between commit:

  f9af88a3d384 ("x86/bugs: Rename MDS machinery to something more generic")

from Linus' tree and commit:

  83ebe7157483 ("KVM: VMX: Apply MMIO Stale Data mitigation if KVM maps MMIO into the guest")

from the kvm-x86 tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc arch/x86/kvm/vmx/vmx.c
index 191a9ed0da22,65949882afa9..000000000000
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@@ -7290,8 -7210,8 +7210,7 @@@ static noinstr void vmx_vcpu_enter_exit
  	if (static_branch_unlikely(&vmx_l1d_should_flush))
  		vmx_l1d_flush(vcpu);
  	else if (static_branch_unlikely(&cpu_buf_vm_clear) &&
- 		 kvm_arch_has_assigned_device(vcpu->kvm))
 -		 (flags & VMX_RUN_CLEAR_CPU_BUFFERS_FOR_MMIO))
 -		mds_clear_cpu_buffers();
 +		x86_clear_cpu_buffers();
  
  	vmx_disable_fb_clear(vmx);
  

Hi all,

On Wed, 9 Jul 2025 16:04:56 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Today's linux-next merge of the kvm-x86 tree got a conflict in:
> 
>   arch/x86/kvm/vmx/vmx.c
> 
> between commit:
> 
>   f9af88a3d384 ("x86/bugs: Rename MDS machinery to something more generic")
> 
> from Linus' tree and commit:
> 
>   83ebe7157483 ("KVM: VMX: Apply MMIO Stale Data mitigation if KVM maps MMIO into the guest")
> 
> from the kvm-x86 tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.

Actually, the resolution is below.

-- 
Cheers,
Stephen Rothwell

diff --cc arch/x86/kvm/vmx/vmx.c
index 191a9ed0da22,65949882afa9..47019c9af671
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@@ -7290,8 -7210,8 +7210,8 @@@ static noinstr void vmx_vcpu_enter_exit
  	if (static_branch_unlikely(&vmx_l1d_should_flush))
  		vmx_l1d_flush(vcpu);
  	else if (static_branch_unlikely(&cpu_buf_vm_clear) &&
- 		 kvm_arch_has_assigned_device(vcpu->kvm))
+ 		 (flags & VMX_RUN_CLEAR_CPU_BUFFERS_FOR_MMIO))
 -		mds_clear_cpu_buffers();
 +		x86_clear_cpu_buffers();
  
  	vmx_disable_fb_clear(vmx);
  

On Wed, Jul 09, 2025 at 05:11:15PM +1000, Stephen Rothwell wrote:
> Hi all,
> 
> On Wed, 9 Jul 2025 16:04:56 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > Today's linux-next merge of the kvm-x86 tree got a conflict in:
> > 
> >   arch/x86/kvm/vmx/vmx.c
> > 
> > between commit:
> > 
> >   f9af88a3d384 ("x86/bugs: Rename MDS machinery to something more generic")
> > 
> > from Linus' tree and commit:
> > 
> >   83ebe7157483 ("KVM: VMX: Apply MMIO Stale Data mitigation if KVM maps MMIO into the guest")
> > 
> > from the kvm-x86 tree.
> > 
> > I fixed it up (see below) and can carry the fix as necessary. This
> > is now fixed as far as linux-next is concerned, but any non trivial
> > conflicts should be mentioned to your upstream maintainer when your tree
> > is submitted for merging.  You may also want to consider cooperating
> > with the maintainer of the conflicting tree to minimise any particularly
> > complex conflicts.
> 
> Actually, the resolution is below.
> 
> -- 
> Cheers,
> Stephen Rothwell
> 
> diff --cc arch/x86/kvm/vmx/vmx.c
> index 191a9ed0da22,65949882afa9..47019c9af671
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@@ -7290,8 -7210,8 +7210,8 @@@ static noinstr void vmx_vcpu_enter_exit
>   	if (static_branch_unlikely(&vmx_l1d_should_flush))
>   		vmx_l1d_flush(vcpu);
>   	else if (static_branch_unlikely(&cpu_buf_vm_clear) &&
> - 		 kvm_arch_has_assigned_device(vcpu->kvm))
> + 		 (flags & VMX_RUN_CLEAR_CPU_BUFFERS_FOR_MMIO))
>  -		mds_clear_cpu_buffers();
>  +		x86_clear_cpu_buffers();
>   
>   	vmx_disable_fb_clear(vmx);
>   

Yap, LGTM.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette