KVM: VMX: Execute WBINVD to keep data consistency with assigned devices
Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 661c6e1..4dfb1dc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -412,6 +412,12 @@
return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
}
+static inline bool cpu_has_vmx_wbinvd_exit(void)
+{
+ return vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_WBINVD_EXITING;
+}
+
static inline bool report_flexpriority(void)
{
return flexpriority_enabled;
@@ -3397,7 +3403,7 @@
static int handle_wbinvd(struct kvm_vcpu *vcpu)
{
skip_emulated_instruction(vcpu);
- /* TODO: Add support for VT-d/pass-through device */
+ kvm_emulate_wbinvd(vcpu);
return 1;
}
@@ -4347,6 +4353,8 @@
.rdtscp_supported = vmx_rdtscp_supported,
.set_supported_cpuid = vmx_set_supported_cpuid,
+
+ .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,
};
static int __init vmx_init(void)