[PULL 3/7] kvm: Add support to KVM_GET_MSR_FEATURE_INDEX_LIST and KVM_GET_MSRS system ioctl

Eduardo Habkost
2018-10-31T00:45:46Z

From: Robert Hoo <robert.hu@linux.intel.com>

Add kvm_get_supported_feature_msrs() to get supported MSR feature index list.
Add kvm_arch_get_supported_msr_feature() to get each MSR features value.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <1539578845-37944-2-git-send-email-robert.hu@linux.intel.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
---
include/sysemu/kvm.h | 2 ++
target/i386/kvm.c | 80 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 0b64b8e067..97d8d9d0d5 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -463,6 +463,8 @@ int kvm_vm_check_extension(KVMState *s, unsigned int extension);

uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
uint32_t index, int reg);
+uint32_t kvm_arch_get_supported_msr_feature(KVMState *s, uint32_t index);
+

void kvm_set_sigmask_len(KVMState *s, unsigned int sigmask_len);

diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 115d8b4c14..161fc38397 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -107,6 +107,7 @@ static int has_pit_state2;
static bool has_msr_mcg_ext_ctl;

static struct kvm_cpuid2 *cpuid_cache;
+static struct kvm_msr_list *kvm_feature_msrs;

int kvm_has_pit_state2(void)
{
@@ -420,6 +421,42 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
return ret;
}

+uint32_t kvm_arch_get_supported_msr_feature(KVMState *s, uint32_t index)
+{
+ struct {
+ struct kvm_msrs info;
+ struct kvm_msr_entry entries[1];
+ } msr_data;
+ uint32_t ret;
+
+ if (kvm_feature_msrs == NULL) { /* Host doesn't support feature MSRs */
+ return 0;
+ }
+
+ /* Check if requested MSR is supported feature MSR */
+ int i;
+ for (i = 0; i < kvm_feature_msrs->nmsrs; i++)
+ if (kvm_feature_msrs->indices[i] == index) {
+ break;
+ }
+ if (i == kvm_feature_msrs->nmsrs) {
+ return 0; /* if the feature MSR is not supported, simply return 0 */
+ }
+
+ msr_data.info.nmsrs = 1;
+ msr_data.entries[0].index = index;
+
+ ret = kvm_ioctl(s, KVM_GET_MSRS, &msr_data);
+ if (ret != 1) {
+ error_report("KVM get MSR (index=0x%x) feature failed, %s",
+ index, strerror(-ret));
+ exit(1);
+ }
+
+ return msr_data.entries[0].data;
+}
+
+
typedef struct HWPoisonPage {
ram_addr_t ram_addr;
QLIST_ENTRY(HWPoisonPage) list;
@@ -1286,6 +1323,47 @@ void kvm_arch_do_init_vcpu(X86CPU *cpu)
}
}

+static int kvm_get_supported_feature_msrs(KVMState *s)
+{
+ int ret = 0;
+
+ if (kvm_feature_msrs != NULL) {
+ return 0;
+ }
+
+ if (!kvm_check_extension(s, KVM_CAP_GET_MSR_FEATURES)) {
+ return 0;
+ }
+
+ struct kvm_msr_list msr_list;
+
+ msr_list.nmsrs = 0;
+ ret = kvm_ioctl(s, KVM_GET_MSR_FEATURE_INDEX_LIST, &msr_list);
+ if (ret < 0 && ret != -E2BIG) {
+ error_report("Fetch KVM feature MSR list failed: %s",
+ strerror(-ret));
+ return ret;
+ }
+
+ assert(msr_list.nmsrs > 0);
+ kvm_feature_msrs = (struct kvm_msr_list *) \
+ g_malloc0(sizeof(msr_list) +
+ msr_list.nmsrs * sizeof(msr_list.indices[0]));
+
+ kvm_feature_msrs->nmsrs = msr_list.nmsrs;
+ ret = kvm_ioctl(s, KVM_GET_MSR_FEATURE_INDEX_LIST, kvm_feature_msrs);
+
+ if (ret < 0) {
+ error_report("Fetch KVM feature MSR list failed: %s",
+ strerror(-ret));
+ g_free(kvm_feature_msrs);
+ kvm_feature_msrs = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
static int kvm_get_supported_msrs(KVMState *s)
{
static int kvm_supported_msrs;
@@ -1439,6 +1517,8 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
return ret;
}

+ kvm_get_supported_feature_msrs(s);
+
uname(&utsname);
lm_capable_kernel = strcmp(utsname.machine, "x86_64") == 0;

--
2.18.0.rc1.1.g3f1ff2140