Messages in this thread | | | Subject | Re: [PATCH] kvm: x86/mmu: Use cpuid to determine max gfn | From | Paolo Bonzini <> | Date | Fri, 4 Dec 2020 09:48:58 +0100 |
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On 04/12/20 01:43, Sean Christopherson wrote: > On Thu, Dec 03, 2020, Rick Edgecombe wrote: >> In the TDP MMU, use shadow_phys_bits to dermine the maximum possible GFN >> mapped in the guest for zapping operations. boot_cpu_data.x86_phys_bits >> may be reduced in the case of HW features that steal HPA bits for other >> purposes. However, this doesn't necessarily reduce GPA space that can be >> accessed via TDP. So zap based on a maximum gfn calculated with MAXPHYADDR >> retrieved from CPUID. This is already stored in shadow_phys_bits, so use >> it instead of x86_phys_bits. >> >> Fixes: faaf05b00aec ("kvm: x86/mmu: Support zapping SPTEs in the TDP MMU") >> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> > > Dang, in hindsight it'd be nice if KVM_CAP_SMALLER_MAXPHYADDR allowed explicitly > setting the max MAXPHYADDR for an entire VM instead of being a simple toggle. > E.g. TDX and SEV-ES likely could also make use of "what's this VM's max GPA?". > > Reviewed-by: Sean Christopherson <seanjc@google.com> >
Queued, thanks.
Paolo
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