diff options
| author | Vitaly Kuznetsov | 2021-06-08 14:08:16 +0200 |
|---|---|---|
| committer | Eduardo Habkost | 2021-07-13 15:13:29 +0200 |
| commit | cce087f628c651e905f5e2097d9bb9f678689669 (patch) | |
| tree | 90b99fcf104166c57a335e0b6d9ace84191bec50 /target/i386 | |
| parent | i386: HV_HYPERCALL_AVAILABLE privilege bit is always needed (diff) | |
| download | qemu-cce087f628c651e905f5e2097d9bb9f678689669.tar.gz qemu-cce087f628c651e905f5e2097d9bb9f678689669.tar.xz qemu-cce087f628c651e905f5e2097d9bb9f678689669.zip | |
i386: Hyper-V SynIC requires POST_MESSAGES/SIGNAL_EVENTS privileges
When Hyper-V SynIC is enabled, we may need to allow Windows guests to make
hypercalls (POST_MESSAGES/SIGNAL_EVENTS). No issue is currently observed
because KVM is very permissive, allowing these hypercalls regarding of
guest visible CPUid bits.
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210608120817.1325125-9-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Diffstat (limited to 'target/i386')
| -rw-r--r-- | target/i386/kvm/hyperv-proto.h | 6 | ||||
| -rw-r--r-- | target/i386/kvm/kvm.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/target/i386/kvm/hyperv-proto.h b/target/i386/kvm/hyperv-proto.h index e30d64b4ad..5fbb385cc1 100644 --- a/target/i386/kvm/hyperv-proto.h +++ b/target/i386/kvm/hyperv-proto.h @@ -39,6 +39,12 @@ #define HV_ACCESS_REENLIGHTENMENTS_CONTROL (1u << 13) /* + * HV_CPUID_FEATURES.EBX bits + */ +#define HV_POST_MESSAGES (1u << 4) +#define HV_SIGNAL_EVENTS (1u << 5) + +/* * HV_CPUID_FEATURES.EDX bits */ #define HV_MWAIT_AVAILABLE (1u << 0) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index eee1a6b46e..59ed8327ac 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1346,6 +1346,12 @@ static int hyperv_fill_cpuids(CPUState *cs, /* Unconditionally required with any Hyper-V enlightenment */ c->eax |= HV_HYPERCALL_AVAILABLE; + /* SynIC and Vmbus devices require messages/signals hypercalls */ + if (hyperv_feat_enabled(cpu, HYPERV_FEAT_SYNIC) && + !cpu->hyperv_synic_kvm_only) { + c->ebx |= HV_POST_MESSAGES | HV_SIGNAL_EVENTS; + } + /* Not exposed by KVM but needed to make CPU hotplug in Windows work */ c->edx |= HV_CPU_DYNAMIC_PARTITIONING_AVAILABLE; |