Skip to contentSkip to conversation

FAILED: patch "[PATCH] KVM: nVMX: fix nested EPT detection" failed to apply to 4.10-stable tree

PATCH [email protected] 1 participant 1 message Mar 30, 2017

Subsystems (3)
Stable branch x86 KVM x86
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 7ad658b693536741c37b16aeb07840a2ce75f5b9 Mon Sep 17 00:00:00 2001

From: Ladi Prosek <[email protected]>
Date: Thu, 23 Mar 2017 07:18:08 +0100
Subject: [PATCH] KVM: nVMX: fix nested EPT detection

The nested_ept_enabled flag introduced in commit 7ca29de2136 was not computed correctly. We are interested only in L1's EPT state, not the the combined L0+L1 value.

In particular, if L0 uses EPT but L1 does not, nested_ept_enabled must be false to make sure that PDPSTRs are loaded based on CR3 as usual, because the special case described in 26.3.2.4 Loading Page-Directory- Pointer-Table Entries does not apply.

Fixes 7ca29de21362 ("KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT")
Cc [email protected]
Reported-by Wanpeng Li <[email protected]>
Reviewed-by David Hildenbrand <[email protected]>
Signed-off-by Ladi Prosek <[email protected]>
Signed-off-by Paolo Bonzini <[email protected]>
arch/x86/kvm/vmx.c +1 -4
index cd1ba62878f3..2ee00dbbbd51 100644
@@ -9992,7 +9992,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	u32 exec_control;
-	bool nested_ept_enabled = false;
 
 	vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
 	vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);

@@ -10139,8 +10138,6 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 				vmcs12->guest_intr_status);
 		}
 
-		nested_ept_enabled = (exec_control & SECONDARY_EXEC_ENABLE_EPT) != 0;
-
 		/*
 		 * Write an illegal value to APIC_ACCESS_ADDR. Later,
 		 * nested_get_vmcs12_pages will either fix it up or

@@ -10303,7 +10300,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 	vmx_set_efer(vcpu, vcpu->arch.efer);
 
 	/* Shadow page tables on either EPT or shadow page tables. */
-	if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_ept_enabled,
+	if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12),
 				entry_failure_code))
 		return 1;