Re: [PATCH] KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop

[Sean Christopherson]

On Fri, 24 Jan 2025 17:18:33 -0800, Sean Christopherson wrote:
> Move the conditional loading of hardware DR6 with the guest's DR6 value
> out of the core .vcpu_run() loop to fix a bug where KVM can load hardware
> with a stale vcpu->arch.dr6.
> 
> When the guest accesses a DR and host userspace isn't debugging the guest,
> KVM disables DR interception and loads the guest's values into hardware on
> VM-Enter and saves them on VM-Exit.  This allows the guest to access DRs
> at will, e.g. so that a sequence of DR accesses to configure a breakpoint
> only generates one VM-Exit.
> 
> [...]

Applied to kvm-x86 fixes, thanks!

[1/1] KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
      https://github.com/kvm-x86/linux/commit/c2fee09fc167

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