Re: [PATCH MANUALSEL 5.14 4/9] KVM: x86: reset pdptrs_from_userspace when exiting smm

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/10/21 15:30, Sasha Levin wrote:
From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

[ Upstream commit 37687c403a641f251cb2ef2e7830b88aa0647ba9 ]

When exiting SMM, pdpts are loaded again from the guest memory.

This fixes a theoretical bug, when exit from SMM triggers entry to the
nested guest which re-uses some of the migration
code which uses this flag as a workaround for a legacy userspace.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Message-Id: <20210913140954.165665-4-mlevitsk@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
  arch/x86/kvm/x86.c | 7 +++++++
  1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b3f855d48f72..1e7d629bbf36 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7659,6 +7659,13 @@ static void kvm_smm_changed(struct kvm_vcpu *vcpu, bool entering_smm)
/* Process a latched INIT or SMI, if any. */
  		kvm_make_request(KVM_REQ_EVENT, vcpu);
+
+		/*
+		 * Even if KVM_SET_SREGS2 loaded PDPTRs out of band,
+		 * on SMM exit we still need to reload them from
+		 * guest memory
+		 */
+		vcpu->arch.pdptrs_from_userspace = false;
  	}
kvm_mmu_reset_context(vcpu);


Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux