Messages in this thread | | | Subject | Re: [PATCH v3 2/3] KVM: x86: Move pkru save/restore to x86.c | From | Babu Moger <> | Date | Tue, 12 May 2020 12:17:59 -0500 |
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On 5/12/20 11:39 AM, Jim Mattson wrote: > On Mon, May 11, 2020 at 4:33 PM Babu Moger <babu.moger@amd.com> wrote: >> >> MPK feature is supported by both VMX and SVM. So we can >> safely move pkru state save/restore to common code. Also >> move all the pkru data structure to kvm_vcpu_arch. >> >> Also fixes the problem Jim Mattson pointed and suggested below. >> >> "Though rdpkru and wrpkru are contingent upon CR4.PKE, the PKRU >> resource isn't. It can be read with XSAVE and written with XRSTOR. >> So, if we don't set the guest PKRU value here(kvm_load_guest_xsave_state), >> the guest can read the host value. >> >> In case of kvm_load_host_xsave_state, guest with CR4.PKE clear could >> potentially use XRSTOR to change the host PKRU value" >> >> Signed-off-by: Babu Moger <babu.moger@amd.com> > > I would do the bugfix as a separate commit, to ease backporting it to > the stable branches.
Ok. Sure.
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