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[Qemu-devel] [PATCH 1/3] expose paravirt feature list to cpuid
From: |
Glauber Costa |
Subject: |
[Qemu-devel] [PATCH 1/3] expose paravirt feature list to cpuid |
Date: |
Wed, 28 Jan 2009 14:02:03 -0500 |
Expose the paravirt features provided by the host to the guest.
The features exposed uses qemu just as a medium, since they only
depend on a negotiation between the host and guest directly.
As a direct result, we're now able to run the kvm pvclock in qemu
based kvm guests.
Signed-off-by: Glauber Costa <address@hidden>
---
kvm.h | 1 +
target-i386/kvm.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/kvm.h b/kvm.h
index efce145..db58baa 100644
--- a/kvm.h
+++ b/kvm.h
@@ -17,6 +17,7 @@
#include "config.h"
#ifdef CONFIG_KVM
+#include <linux/kvm_para.h>
extern int kvm_allowed;
#define kvm_enabled() (kvm_allowed)
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 2412ae4..7f4e5aa 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -33,16 +33,61 @@
do { } while (0)
#endif
+struct kvm_para_features {
+ int cap;
+ int feature;
+} para_features[] = {
+#ifdef KVM_CAP_CLOCKSOURCE
+ { KVM_CAP_CLOCKSOURCE, KVM_FEATURE_CLOCKSOURCE },
+#endif
+#ifdef KVM_CAP_NOP_IO_DELAY
+ { KVM_CAP_NOP_IO_DELAY, KVM_FEATURE_NOP_IO_DELAY },
+#endif
+#ifdef KVM_CAP_PV_MMU
+ { KVM_CAP_PV_MMU, KVM_FEATURE_MMU_OP },
+#endif
+#ifdef KVM_CAP_CR3_CACHE
+ { KVM_CAP_CR3_CACHE, KVM_FEATURE_CR3_CACHE },
+#endif
+};
+
+static uint32_t get_para_features(CPUState *env)
+{
+ uint32_t i, features = 0;
+
+ for (i = 0; i < ARRAY_SIZE(para_features); i++) {
+ if (kvm_ioctl(env->kvm_state, KVM_CHECK_EXTENSION,
para_features[i].cap))
+ features |= (1 << para_features[i].feature);
+ }
+
+ return features;
+}
int kvm_arch_init_vcpu(CPUState *env)
{
struct {
struct kvm_cpuid cpuid;
struct kvm_cpuid_entry entries[100];
} __attribute__((packed)) cpuid_data;
- uint32_t limit, i, cpuid_i;
+ uint32_t limit, i, cpuid_i = 0;
uint32_t eax, ebx, ecx, edx;
+#ifdef KVM_CPUID_SIGNATURE
+ struct kvm_cpuid_entry *pv_ent;
+
+ /* Paravirtualization CPUIDs */
+ pv_ent = &cpuid_data.entries[cpuid_i++];
+ memset(pv_ent, 0, sizeof(*pv_ent));
+ pv_ent->function = KVM_CPUID_SIGNATURE;
+ pv_ent->eax = 0;
+ pv_ent->ebx = 0x4b4d564b; /* KVMKVMK */
+ pv_ent->ecx = 0x564b4d56; /* VMKV */
+ pv_ent->edx = 0x0000004d; /* M */
+
+ pv_ent = &cpuid_data.entries[cpuid_i++];
+ memset(pv_ent, 0, sizeof(*pv_ent));
+ pv_ent->function = KVM_CPUID_FEATURES;
+ pv_ent->eax = get_para_features(env);
+#endif
- cpuid_i = 0;
cpu_x86_cpuid(env, 0, &eax, &ebx, &ecx, &edx);
limit = eax;
--
1.5.6.5