Messages in this thread | | | From | Haiwei Li <> | Date | Fri, 9 Apr 2021 09:57:57 +0800 | Subject | Re: [PATCH] KVM: vmx: add mismatched size in vmcs_check32 |
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On Fri, Apr 9, 2021 at 12:05 AM Sean Christopherson <seanjc@google.com> wrote: > > On Thu, Apr 08, 2021, lihaiwei.kernel@gmail.com wrote: > > From: Haiwei Li <lihaiwei@tencent.com> > > > > vmcs_check32 misses the check for 64-bit and 64-bit high. > > Can you clarify in the changelog that, while it is architecturally legal to > access 64-bit and 64-bit high fields with a 32-bit read/write in 32-bit mode, > KVM should never do partial accesses to VMCS fields. And/or note that the > 32-bit accesses are done in vmcs_{read,write}64() when necessary? Hmm, maybe: > > Add compile-time assertions in vmcs_check32() to disallow accesses to > 64-bit and 64-bit high fields via vmcs_{read,write}32(). Upper level > KVM code should never do partial accesses to VMCS fields. KVM handles > the split accesses automatically in vmcs_{read,write}64() when running > as a 32-bit kernel.
Good suggestion, thanks. I will send v2.
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