KVM: x86: fix ordering of cr0 initialization code in vmx_cpu_reset

Commit d28bc9dd25ce reversed the order of two lines which initialize cr0,
allowing the current (old) cr0 value to mess up vcpu initialization.
This was observed in the checks for cr0 X86_CR0_WP bit in the context of
kvm_mmu_reset_context(). Besides, setting vcpu->arch.cr0 after vmx_set_cr0()
is completely redundant. Change the order back to ensure proper vcpu
initialization.

The combination of booting with ovmf firmware when guest vcpus > 1 and kvm's
ept=N option being set results in a VM-entry failure. This patch fixes that.

Fixes: d28bc9dd25ce ("KVM: x86: INIT and reset sequences are different")
Cc: stable@vger.kernel.org
Signed-off-by: Bruce Rogers <brogers@suse.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ee1c8a93871c551f9cddc93de56197806d0c0cfd..ab4a387b98b16a7d4d4d938f6187ed11b8e25271 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5046,8 +5046,8 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
                vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);
 
        cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
-       vmx_set_cr0(vcpu, cr0); /* enter rmode */
        vmx->vcpu.arch.cr0 = cr0;
+       vmx_set_cr0(vcpu, cr0); /* enter rmode */
        vmx_set_cr4(vcpu, 0);
        vmx_set_efer(vcpu, 0);
        vmx_fpu_activate(vcpu);