From 83d31e5271ac74aad14b5a1a2ed26923e1446329 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 9 Jul 2020 13:12:09 -0400
Subject: [PATCH] KVM: nVMX: fixes for preemption timer migration
Commit 850448f35aaf ("KVM: nVMX: Fix VMX preemption timer migration",
2020-06-01) accidentally broke nVMX live migration from older version
by changing the userspace ABI. Restore it and, while at it, ensure
that vmx->nested.has_preemption_timer_deadline is always initialized
according to the KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE flag.
Cc: Makarand Sonare <makarandsonare@google.com>
Fixes: 850448f35aaf ("KVM: nVMX: Fix VMX preemption timer migration")
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
Documentation/virt/kvm/api.rst | 5 +++--
arch/x86/include/uapi/asm/kvm.h | 5 +++--
arch/x86/kvm/vmx/nested.c | 1 +
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 426f94582b7a1..320788f81a051 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -4339,14 +4339,15 @@ Errors:
#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
struct kvm_vmx_nested_state_hdr {
- __u32 flags;
__u64 vmxon_pa;
__u64 vmcs12_pa;
- __u64 preemption_timer_deadline;
struct {
__u16 flags;
} smm;
+
+ __u32 flags;
+ __u64 preemption_timer_deadline;
};
struct kvm_vmx_nested_state_data {
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 17c5a038f42d3..0780f97c18508 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -408,14 +408,15 @@ struct kvm_vmx_nested_state_data {
};
struct kvm_vmx_nested_state_hdr {
- __u32 flags;
__u64 vmxon_pa;
__u64 vmcs12_pa;
- __u64 preemption_timer_deadline;
struct {
__u16 flags;
} smm;
+
+ __u32 flags;
+ __u64 preemption_timer_deadline;
};
struct kvm_svm_nested_state_data {
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b26655104d4a9..d4a4cec034d00 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6176,6 +6176,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
goto error_guest_mode;
}
+ vmx->nested.has_preemption_timer_deadline = false;
if (kvm_state->hdr.vmx.flags & KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE) {
vmx->nested.has_preemption_timer_deadline = true;
vmx->nested.preemption_timer_deadline =
--
2.30.2