linux-kernel - [PATCH v2 2/6] KVM: x86: force PDPTR reload on SMM exit

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Message-Id: <20210830125539.1768833-3-mlevitsk@redhat.com>
Date:   Mon, 30 Aug 2021 15:55:35 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Jim Mattson <jmattson@...gle.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
        Ingo Molnar <mingo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND
        64-BIT)), Joerg Roedel <joro@...tes.org>,
        Wanpeng Li <wanpengli@...cent.com>,
        "H. Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...en8.de>
Subject: [PATCH v2 2/6] KVM: x86: force PDPTR reload on SMM exit

KVM_REQ_GET_NESTED_STATE_PAGES is also used on VM entries
that happen on exit from SMM mode, and in this case PDPTRS
must be always reloaded

Fixes: 0f85722341b0 ("KVM: nVMX: delay loading of PDPTRs to KVM_REQ_GET_NESTED_STATE_PAGES")
Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/kvm/vmx/vmx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index fada1055f325..4194fbf5e5d6 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7504,6 +7504,13 @@ static int vmx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
 	}
 
 	if (vmx->nested.smm.guest_mode) {
+
+		/* Exit from the SMM to the non root mode also uses
+		 * the KVM_REQ_GET_NESTED_STATE_PAGES request,
+		 * but in this case the pdptrs must be always reloaded
+		 */
+		vcpu->arch.pdptrs_from_userspace = false;
+
 		ret = nested_vmx_enter_non_root_mode(vcpu, false);
 		if (ret)
 			return ret;
-- 
2.26.3