From 0baa4b445e28f37243e5dc72e7efe32f0c9d7801 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Thu, 23 Jul 2020 16:27:01 +0200 Subject: [PATCH] KVM: fix CPU reset wrt HF2_GIF_MASK HF2_GIF_MASK is set in env->hflags2 unconditionally on CPU reset (see x86_cpu_reset()) but when calling KVM_SET_NESTED_STATE, KVM_STATE_NESTED_GIF_SET is only valid for nSVM as e.g. nVMX code looks like if (kvm_state->hdr.vmx.vmxon_pa == -1ull) { if (kvm_state->flags & ~KVM_STATE_NESTED_EVMCS) return -EINVAL; } Also, when adjusting the environment after KVM_GET_NESTED_STATE we need not reset HF2_GIF_MASK on VMX as e.g. x86_cpu_pending_interrupt() expects it to be set. Alternatively, we could've made env->hflags2 SVM-only. Reported-by: Jan Kiszka Fixes: b16c0e20c742 ("KVM: add support for AMD nested live migration") Signed-off-by: Vitaly Kuznetsov Message-Id: <20200723142701.2521161-1-vkuznets@redhat.com> Tested-by: Jan Kiszka Signed-off-by: Eduardo Habkost --- target/i386/kvm.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index b8455c89ed..6f18d940a5 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -3877,7 +3877,9 @@ static int kvm_put_nested_state(X86CPU *cpu) } else { env->nested_state->flags &= ~KVM_STATE_NESTED_GUEST_MODE; } - if (env->hflags2 & HF2_GIF_MASK) { + + /* Don't set KVM_STATE_NESTED_GIF_SET on VMX as it is illegal */ + if (cpu_has_svm(env) && (env->hflags2 & HF2_GIF_MASK)) { env->nested_state->flags |= KVM_STATE_NESTED_GIF_SET; } else { env->nested_state->flags &= ~KVM_STATE_NESTED_GIF_SET; @@ -3919,10 +3921,14 @@ static int kvm_get_nested_state(X86CPU *cpu) } else { env->hflags &= ~HF_GUEST_MASK; } - if (env->nested_state->flags & KVM_STATE_NESTED_GIF_SET) { - env->hflags2 |= HF2_GIF_MASK; - } else { - env->hflags2 &= ~HF2_GIF_MASK; + + /* Keep HF2_GIF_MASK set on !SVM as x86_cpu_pending_interrupt() needs it */ + if (cpu_has_svm(env)) { + if (env->nested_state->flags & KVM_STATE_NESTED_GIF_SET) { + env->hflags2 |= HF2_GIF_MASK; + } else { + env->hflags2 &= ~HF2_GIF_MASK; + } } return ret; -- 2.11.0