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target-i386: kvm: Allocate kvm_msrs struct once per VCPU

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Instead of using 2400 bytes in the stack for 150 MSR entries in
kvm_get_msrs() and kvm_put_msrs(), allocate a buffer once for
each VCPU.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
Eduardo Habkost 2015-12-16 17:06:42 -02:00
parent 42ecabaae1
commit d71b62a165
2 changed files with 23 additions and 18 deletions
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4
target-i386/cpu.h
View File

@ -1124,6 +1124,8 @@ typedef struct CPUX86State {
TPRAccess tpr_access_type;
} CPUX86State;
struct kvm_msrs;
/**
* X86CPU:
* @env: #CPUX86State
@ -1176,6 +1178,8 @@ struct X86CPU {
struct DeviceState *apic_state;
struct MemoryRegion *cpu_as_root, *cpu_as_mem, *smram;
Notifier machine_done;
struct kvm_msrs *kvm_msr_buf;
};
static inline X86CPU *x86_env_get_cpu(CPUX86State *env)

37
target-i386/kvm.c
View File

@ -57,6 +57,9 @@
#define MSR_KVM_WALL_CLOCK 0x11
#define MSR_KVM_SYSTEM_TIME 0x12
#define MSR_BUF_SIZE \
(sizeof(struct kvm_msrs) + 150 * sizeof(struct kvm_msr_entry))
#ifndef BUS_MCEERR_AR
#define BUS_MCEERR_AR 4
#endif
@ -914,6 +917,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
if (has_xsave) {
env->kvm_xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave));
}
cpu->kvm_msr_buf = g_malloc0(MSR_BUF_SIZE);
if (env->features[FEAT_1_EDX] & CPUID_MTRR) {
has_msr_mtrr = true;
@ -1462,6 +1466,11 @@ static void kvm_msr_entry_set(struct kvm_msr_entry *entry,
entry->data = value;
}
static void kvm_msr_buf_reset(X86CPU *cpu)
{
memset(cpu->kvm_msr_buf, 0, MSR_BUF_SIZE);
}
static int kvm_put_tscdeadline_msr(X86CPU *cpu)
{
CPUX86State *env = &cpu->env;
@ -1528,14 +1537,12 @@ static int kvm_put_msr_feature_control(X86CPU *cpu)
static int kvm_put_msrs(X86CPU *cpu, int level)
{
CPUX86State *env = &cpu->env;
struct {
struct kvm_msrs info;
struct kvm_msr_entry entries[150];
} msr_data;
struct kvm_msr_entry *msrs = msr_data.entries;
struct kvm_msr_entry *msrs = cpu->kvm_msr_buf->entries;
int n = 0, i;
int ret;
kvm_msr_buf_reset(cpu);
kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_CS, env->sysenter_cs);
kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_ESP, env->sysenter_esp);
kvm_msr_entry_set(&msrs[n++], MSR_IA32_SYSENTER_EIP, env->sysenter_eip);
@ -1724,11 +1731,9 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
}
}
msr_data.info = (struct kvm_msrs) {
.nmsrs = n,
};
cpu->kvm_msr_buf->nmsrs = n;
ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, &msr_data);
ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MSRS, cpu->kvm_msr_buf);
if (ret < 0) {
return ret;
}
@ -1944,13 +1949,11 @@ static int kvm_get_sregs(X86CPU *cpu)
static int kvm_get_msrs(X86CPU *cpu)
{
CPUX86State *env = &cpu->env;
struct {
struct kvm_msrs info;
struct kvm_msr_entry entries[150];
} msr_data;
struct kvm_msr_entry *msrs = msr_data.entries;
struct kvm_msr_entry *msrs = cpu->kvm_msr_buf->entries;
int ret, i, n;
kvm_msr_buf_reset(cpu);
n = 0;
msrs[n++].index = MSR_IA32_SYSENTER_CS;
msrs[n++].index = MSR_IA32_SYSENTER_ESP;
@ -2092,11 +2095,9 @@ static int kvm_get_msrs(X86CPU *cpu)
}
}
msr_data.info = (struct kvm_msrs) {
.nmsrs = n,
};
cpu->kvm_msr_buf->nmsrs = n;
ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MSRS, &msr_data);
ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MSRS, cpu->kvm_msr_buf);
if (ret < 0) {
return ret;
}