Messages in this thread | | | Date | Fri, 25 Nov 2022 08:12:16 +0800 | From | Yan Zhao <> | Subject | Re: [PATCH v10 035/108] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis |
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On Fri, Nov 25, 2022 at 08:13:48AM +0800, Huang, Kai wrote: > On Tue, 2022-11-22 at 10:10 +0800, Yan Zhao wrote: > > Also make enable_mmio_caching to be a per-VM value? > > As if the shadow_mmio_value is 0, mmio_caching needs to be disabled. > > If I recall correctly, Sean said we can disable TDX guests if mmio_caching is > disabled (we also will need to change to allow enable_mmio_caching to still be > true when mmio_value is 0). > > SEV_ES has similar logic: > > void __init sev_hardware_setup(void) > { > > ... > > /* > * SEV-ES requires MMIO caching as KVM doesn't have access to the guest > * instruction stream, i.e. can't emulate in response to a #NPF and > * instead relies on #NPF(RSVD) being reflected into the guest as #VC > * (the guest can then do a #VMGEXIT to request MMIO emulation). > */ > if (!enable_mmio_caching) > goto out; >
Would enabling mmio caching in per-VM basis be better?
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