qemu-kvm/SOURCES/kvm-i386-cpu-make-cpu-host-support-monitor-mwait.patch

133 lines
4.8 KiB
Diff

From 91ac1f511b0414292d07688c3cb3012bed6e3649 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Fri, 22 Jun 2018 22:22:05 +0300
Subject: [PATCH 09/11] 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>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
accel/tcg/user-exec-stub.c | 3 +++
target/i386/cpu.c | 32 ++++++++++++++++++++++----------
target/i386/cpu.h | 9 +++++++++
target/i386/kvm.c | 9 +++++++++
4 files changed, 43 insertions(+), 10 deletions(-)
diff --git a/accel/tcg/user-exec-stub.c b/accel/tcg/user-exec-stub.c
index dbcf1ad..a32b449 100644
--- a/accel/tcg/user-exec-stub.c
+++ b/accel/tcg/user-exec-stub.c
@@ -2,6 +2,9 @@
#include "qemu-common.h"
#include "qom/cpu.h"
#include "sysemu/replay.h"
+#include "sysemu/sysemu.h"
+
+bool enable_cpu_pm = false;
void cpu_resume(CPUState *cpu)
{
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 307b629..87b0502 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5662,11 +5662,11 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
}
break;
case 5:
- /* mwait info: needed for Core compatibility */
- *eax = 0; /* Smallest monitor-line size in bytes */
- *ebx = 0; /* Largest monitor-line size in bytes */
- *ecx = CPUID_MWAIT_EMX | CPUID_MWAIT_IBE;
- *edx = 0;
+ /* MONITOR/MWAIT Leaf */
+ *eax = cpu->mwait.eax; /* Smallest monitor-line size in bytes */
+ *ebx = cpu->mwait.ebx; /* Largest monitor-line size in bytes */
+ *ecx = cpu->mwait.ecx; /* flags */
+ *edx = cpu->mwait.edx; /* mwait substates */
break;
case 6:
/* Thermal and Power Leaf */
@@ -6521,13 +6521,25 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
Error *local_err = NULL;
static bool ht_warned;
- if (xcc->host_cpuid_required && !accel_uses_host_cpuid()) {
- char *name = x86_cpu_class_get_model_name(xcc);
- error_setg(&local_err, "CPU model '%s' requires KVM", name);
- g_free(name);
- goto out;
+ if (xcc->host_cpuid_required) {
+ if (!accel_uses_host_cpuid()) {
+ char *name = x86_cpu_class_get_model_name(xcc);
+ error_setg(&local_err, "CPU model '%s' requires KVM", name);
+ g_free(name);
+ goto out;
+ }
+
+ if (enable_cpu_pm) {
+ host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx,
+ &cpu->mwait.ecx, &cpu->mwait.edx);
+ env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
+ }
}
+ /* mwait extended info: needed for Core compatibility */
+ /* We always wake on interrupt even if host does not have the capability */
+ cpu->mwait.ecx |= CPUID_MWAIT_EMX | CPUID_MWAIT_IBE;
+
if (cpu->apic_id == UNASSIGNED_APIC_ID) {
error_setg(errp, "apic-id property was not initialized properly");
return;
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index d33fa8d..7ab8ee9 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1564,6 +1564,15 @@ struct X86CPU {
/* if true the CPUID code directly forward host cache leaves to the guest */
bool cache_info_passthrough;
+ /* if true the CPUID code directly forwards
+ * host monitor/mwait leaves to the guest */
+ struct {
+ uint32_t eax;
+ uint32_t ebx;
+ uint32_t ecx;
+ uint32_t edx;
+ } mwait;
+
/* Features that were filtered out because of missing host capabilities */
FeatureWordArray filtered_features;
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 879c3e0..ffd01f0 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -377,6 +377,15 @@ 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) {
--
1.8.3.1