Paolo Bonzini d2df592fd8 KVM: nSVM: prepare guest save area while is_guest_mode is true ... Right now, enter_svm_guest_mode is calling nested_prepare_vmcb_save and nested_prepare_vmcb_control. This results in is_guest_mode being false until the end of nested_prepare_vmcb_control. This is a problem because nested_prepare_vmcb_save can in turn cause changes to the intercepts and these have to be applied to the "host VMCB" (stored in svm->nested.hsave) and then merged with the VMCB12 intercepts into svm->vmcb. In particular, without this change we forget to set the CR0 read and CR0 write intercepts when running a real mode L2 guest with NPT disabled. The guest is therefore able to see the CR0.PG bit that KVM sets to enable "paged real mode". This patch fixes the svm.flat mode_switch test case with npt=0. There are no other problematic calls in nested_prepare_vmcb_save. Moving is_guest_mode to the end is done since commit 06fc777269 ("KVM: SVM: Activate nested state only when guest state is complete", 2010-04-25). However, back then KVM didn't grab a different VMCB when updating the intercepts, it had already copied/merged L1's stuff to L0's VMCB, and then updated L0's VMCB regardless of is_nested(). Later recalc_intercepts was introduced in commit 384c636843 ("KVM: SVM: Add function to recalculate intercept masks", 2011-01-12). This introduced the bug, because recalc_intercepts now throws away the intercept manipulations that svm_set_cr0 had done in the meanwhile to svm->vmcb. [1] https://lore.kernel.org/kvm/1266493115-28386-1-git-send-email-joerg.roedel@amd.com/ Reviewed-by: Sean Christopherson <seanjc@google.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2021-02-22 13:11:56 -05:00
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avic.c	KVM: SVM: Move AVIC vCPU kicking snippet to helper function	2021-02-09 08:17:06 -05:00
nested.c	KVM: nSVM: prepare guest save area while is_guest_mode is true	2021-02-22 13:11:56 -05:00
pmu.c	KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in	2020-06-01 04:26:08 -04:00
sev.c	KVM: SVM: use .prepare_guest_switch() to handle CPU register save/setup	2021-02-04 05:27:35 -05:00
svm_ops.h	KVM: SVM: use vmsave/vmload for saving/restoring additional host state	2021-02-04 05:27:34 -05:00
svm.c	KVM: x86: Advertise INVPCID by default	2021-02-18 07:33:29 -05:00
svm.h	KVM: SVM: use .prepare_guest_switch() to handle CPU register save/setup	2021-02-04 05:27:35 -05:00
vmenter.S	KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests	2020-12-15 05:20:59 -05:00