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authorPaolo Bonzini <pbonzini@redhat.com>2016-07-06 13:23:51 +0200
committerYunhong Jiang <yunhong.jiang@linux.intel.com>2016-07-18 08:10:40 -0700
commit594e1a937a4a019862f6b6e14516bd4e4be9e16f (patch)
tree3e0cc17919b7c018c1ee7050773741ca6932fb53 /kernel/arch/x86/kvm
parentae6912551e1bc31e4b846221b7cf5ec2aac76104 (diff)
KVM: nVMX: keep preemption timer enabled during L2 execution
Because the vmcs12 preemption timer is emulated through a separate hrtimer, we can keep on using the preemption timer in the vmcs02 to emulare L1's TSC deadline timer. However, the corresponding bit in the pin-based execution control field must be kept consistent between vmcs01 and vmcs02. On vmentry we copy it into the vmcs02; on vmexit the preemption timer must be disabled in the vmcs01 if a preemption timer vmexit happened while in guest mode. The preemption timer value in the vmcs02 is set by vmx_vcpu_run, so it need not be considered in prepare_vmcs02. Cc: Yunhong Jiang <yunhong.jiang@intel.com> Cc: Haozhong Zhang <haozhong.zhang@intel.com> Tested-by: Wanpeng Li <kernellwp@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Change-Id: Iffaea7689d4e653dc6224a6f05c6e5ba2fb5c8a8 upstream-status: backport Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
Diffstat (limited to 'kernel/arch/x86/kvm')
-rw-r--r--kernel/arch/x86/kvm/vmx.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/arch/x86/kvm/vmx.c b/kernel/arch/x86/kvm/vmx.c
index 937898646..a722f724c 100644
--- a/kernel/arch/x86/kvm/vmx.c
+++ b/kernel/arch/x86/kvm/vmx.c
@@ -9631,9 +9631,14 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
vmcs_write64(VMCS_LINK_POINTER, -1ull);
exec_control = vmcs12->pin_based_vm_exec_control;
- exec_control |= vmcs_config.pin_based_exec_ctrl;
+
+ /* Preemption timer setting is only taken from vmcs01. */
exec_control &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
+ exec_control |= vmcs_config.pin_based_exec_ctrl;
+ if (vmx->hv_deadline_tsc == -1)
+ exec_control &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
+ /* Posted interrupts setting is only taken from vmcs12. */
if (nested_cpu_has_posted_intr(vmcs12)) {
/*
* Note that we use L0's vector here and in
@@ -10562,8 +10567,14 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
load_vmcs12_host_state(vcpu, vmcs12);
- /* Update TSC_OFFSET if TSC was changed while L2 ran */
+ /* Update any VMCS fields that might have changed while L2 ran */
vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset);
+ if (vmx->hv_deadline_tsc == -1)
+ vmcs_clear_bits(PIN_BASED_VM_EXEC_CONTROL,
+ PIN_BASED_VMX_PREEMPTION_TIMER);
+ else
+ vmcs_set_bits(PIN_BASED_VM_EXEC_CONTROL,
+ PIN_BASED_VMX_PREEMPTION_TIMER);
/* This is needed for same reason as it was needed in prepare_vmcs02 */
vmx->host_rsp = 0;