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| author | Michael S. Tsirkin <mst@redhat.com> | 2018-06-22 22:22:05 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-06-29 13:02:47 +0200 |
| commit | 2266d44311321a833d569cd4deb46cca6021d0e7 (patch) | |
| tree | 954cac47b13360c4ebafbc3f7cb2c4c2c31f9672 /target/i386/kvm.c | |
| parent | 6f131f13e68d648a8e4f083c667ab1acd88ce4cd (diff) | |
| download | qemu-2266d44311321a833d569cd4deb46cca6021d0e7.zip | |
i386/cpu: make -cpu host support monitor/mwait
When guest CPU PM is enabled, and with -cpu host, expose the host CPU
MWAIT leaf in the CPUID so guest can make good PM decisions.
Note: the result is 100% CPU utilization reported by host as host
no longer knows that the CPU is halted.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20180622192148.178309-3-mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'target/i386/kvm.c')
| -rw-r--r-- | target/i386/kvm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/target/i386/kvm.c b/target/i386/kvm.c index dc991f6aca..c5f72d645b 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -366,6 +366,15 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (!kvm_irqchip_in_kernel()) { ret &= ~CPUID_EXT_X2APIC; } + + if (enable_cpu_pm) { + int disable_exits = kvm_check_extension(s, + KVM_CAP_X86_DISABLE_EXITS); + + if (disable_exits & KVM_X86_DISABLE_EXITS_MWAIT) { + ret |= CPUID_EXT_MONITOR; + } + } } else if (function == 6 && reg == R_EAX) { ret |= CPUID_6_EAX_ARAT; /* safe to allow because of emulated APIC */ } else if (function == 7 && index == 0 && reg == R_EBX) { |