x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs
commit 989e3992d2eca32c3f1404f2bc91acda3aa122d8 upstream
The IA32_FLUSH_CMD MSR needs only to be written on VMENTER. Extend
add_atomic_switch_msr() with an entry_only parameter to allow storing the
MSR only in the guest (ENTRY) MSR array.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e4ccb93..e868c06 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2038,9 +2038,9 @@
}
static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
- u64 guest_val, u64 host_val)
+ u64 guest_val, u64 host_val, bool entry_only)
{
- int i, j;
+ int i, j = 0;
struct msr_autoload *m = &vmx->msr_autoload;
switch (msr) {
@@ -2076,7 +2076,9 @@
}
i = find_msr(&m->guest, msr);
- j = find_msr(&m->host, msr);
+ if (!entry_only)
+ j = find_msr(&m->host, msr);
+
if (i == NR_AUTOLOAD_MSRS || j == NR_AUTOLOAD_MSRS) {
printk_once(KERN_WARNING "Not enough msr switch entries. "
"Can't add msr %x\n", msr);
@@ -2086,12 +2088,16 @@
i = m->guest.nr++;
vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, m->guest.nr);
}
+ m->guest.val[i].index = msr;
+ m->guest.val[i].value = guest_val;
+
+ if (entry_only)
+ return;
+
if (j < 0) {
j = m->host.nr++;
vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->host.nr);
}
- m->guest.val[i].index = msr;
- m->guest.val[i].value = guest_val;
m->host.val[j].index = msr;
m->host.val[j].value = host_val;
}
@@ -2150,7 +2156,7 @@
guest_efer &= ~EFER_LME;
if (guest_efer != host_efer)
add_atomic_switch_msr(vmx, MSR_EFER,
- guest_efer, host_efer);
+ guest_efer, host_efer, false);
return false;
} else {
guest_efer &= ~ignore_bits;
@@ -3314,7 +3320,7 @@
vcpu->arch.ia32_xss = data;
if (vcpu->arch.ia32_xss != host_xss)
add_atomic_switch_msr(vmx, MSR_IA32_XSS,
- vcpu->arch.ia32_xss, host_xss);
+ vcpu->arch.ia32_xss, host_xss, false);
else
clear_atomic_switch_msr(vmx, MSR_IA32_XSS);
break;
@@ -8985,7 +8991,7 @@
clear_atomic_switch_msr(vmx, msrs[i].msr);
else
add_atomic_switch_msr(vmx, msrs[i].msr, msrs[i].guest,
- msrs[i].host);
+ msrs[i].host, false);
}
void vmx_arm_hv_timer(struct kvm_vcpu *vcpu)