From: Jing Liu <jing2....@intel.com>
When dynamic xfeatures (e.g. AMX) are used by the guest, the xsave
area would be larger than 4KB. KVM_GET_XSAVE2 and KVM_SET_XSAVE
under KVM_CAP_XSAVE2 works with a xsave buffer larger than 4KB.
Always use the new ioctls under KVM_CAP_XSAVE2 when KVM supports it.
Signed-off-by: Jing Liu <jing2....@intel.com>
Signed-off-by: Zeng Guang <guang.z...@intel.com>
Signed-off-by: Wei Wang <wei.w.w...@intel.com>
Signed-off-by: Yang Zhong <yang.zh...@intel.com>
---
linux-headers/asm-x86/kvm.h | 14 +++++++++++++
linux-headers/linux/kvm.h | 2 ++
target/i386/cpu.h | 4 ++++
target/i386/kvm/kvm.c | 42 ++++++++++++++++++++++++-------------
target/i386/xsave_helper.c | 35 +++++++++++++++++++++++++++++++
5 files changed, 82 insertions(+), 15 deletions(-)
diff --git a/linux-headers/asm-x86/kvm.h b/linux-headers/asm-x86/kvm.h
index 5a776a08f7..2e37b825cd 100644
--- a/linux-headers/asm-x86/kvm.h
+++ b/linux-headers/asm-x86/kvm.h
@@ -375,7 +375,21 @@ struct kvm_debugregs {
/* for KVM_CAP_XSAVE */
struct kvm_xsave {
+ /*
+ * KVM_GET_XSAVE2 and KVM_SET_XSAVE write and read as many bytes
+ * as are returned by KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2)
+ * respectively, when invoked on the vm file descriptor.
+ *
+ * The size value returned by KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2)
+ * will always be at least 4096. Currently, it is only greater
+ * than 4096 if a dynamic feature has been enabled with
+ * ``arch_prctl()``, but this may change in the future.
+ *
+ * The offsets of the state save areas in struct kvm_xsave follow
+ * the contents of CPUID leaf 0xD on the host.
+ */
__u32 region[1024];
+ __u32 extra[0];
};
#define KVM_MAX_XCRS 16
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 02c5e7b7bb..af67be1b9e 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -1130,6 +1130,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_BINARY_STATS_FD 203
#define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
#define KVM_CAP_ARM_MTE 205
+#define KVM_CAP_XSAVE2 208
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1550,6 +1551,7 @@ struct kvm_s390_ucas_mapping {
/* Available with KVM_CAP_XSAVE */
#define KVM_GET_XSAVE _IOR(KVMIO, 0xa4, struct kvm_xsave)
#define KVM_SET_XSAVE _IOW(KVMIO, 0xa5, struct kvm_xsave)
+#define KVM_GET_XSAVE2 _IOR(KVMIO, 0xcf, struct kvm_xsave)
/* Available with KVM_CAP_XCRS */
#define KVM_GET_XCRS _IOR(KVMIO, 0xa6, struct kvm_xcrs)
#define KVM_SET_XCRS _IOW(KVMIO, 0xa7, struct kvm_xcrs)
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index f7fc2e97a6..de9da38e42 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1528,6 +1528,10 @@ typedef struct CPUX86State {
uint64_t opmask_regs[NB_OPMASK_REGS];
YMMReg zmmh_regs[CPU_NB_REGS];
ZMMReg hi16_zmm_regs[CPU_NB_REGS];
+#ifdef TARGET_X86_64
+ uint8_t xtilecfg[64];
+ uint8_t xtiledata[8192];
+#endif
/* sysenter registers */
uint32_t sysenter_cs;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 25d26a15f8..5f931fbbc6 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -122,6 +122,7 @@ static uint32_t num_architectural_pmu_gp_counters;
static uint32_t num_architectural_pmu_fixed_counters;
static int has_xsave;
+static int has_xsave2;
static int has_xcrs;
static int has_pit_state2;
static int has_sregs2;
@@ -1571,6 +1572,26 @@ static Error *invtsc_mig_blocker;
#define KVM_MAX_CPUID_ENTRIES 100
+static void kvm_init_xsave(CPUX86State *env)
+{
+ if (has_xsave2) {
+ env->xsave_buf_len = QEMU_ALIGN_UP(has_xsave2, 4096);
+ } else if (has_xsave) {
+ env->xsave_buf_len = sizeof(struct kvm_xsave);
+ } else {
+ return;
+ }
+
+ env->xsave_buf = qemu_memalign(4096, env->xsave_buf_len);
+ memset(env->xsave_buf, 0, env->xsave_buf_len);
+ /*
+ * The allocated storage must be large enough for all of the
+ * possible XSAVE state components.
+ */
+ assert(kvm_arch_get_supported_cpuid(kvm_state, 0xd, 0, R_ECX) <=
+ env->xsave_buf_len);
+}
+
int kvm_arch_init_vcpu(CPUState *cs)
{
struct {
@@ -1600,6 +1621,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
cpuid_i = 0;
+ has_xsave2 = kvm_check_extension(cs->kvm_state, KVM_CAP_XSAVE2);
+
r = kvm_arch_set_tsc_khz(cs);
if (r < 0) {
return r;
@@ -1988,19 +2011,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
if (r) {
goto fail;
}
-
- if (has_xsave) {
- env->xsave_buf_len = sizeof(struct kvm_xsave);
- env->xsave_buf = qemu_memalign(4096, env->xsave_buf_len);
- memset(env->xsave_buf, 0, env->xsave_buf_len);
-
- /*
- * The allocated storage must be large enough for all of the
- * possible XSAVE state components.
- */
- assert(kvm_arch_get_supported_cpuid(kvm_state, 0xd, 0, R_ECX)
- <= env->xsave_buf_len);
- }
+ kvm_init_xsave(env);
max_nested_state_len = kvm_max_nested_state_length();
if (max_nested_state_len > 0) {
@@ -3304,13 +3315,14 @@ static int kvm_get_xsave(X86CPU *cpu)
{
CPUX86State *env = &cpu->env;
void *xsave = env->xsave_buf;
- int ret;
+ int type, ret;
if (!has_xsave) {
return kvm_get_fpu(cpu);
}
- ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_XSAVE, xsave);
+ type = has_xsave2 ? KVM_GET_XSAVE2 : KVM_GET_XSAVE;
+ ret = kvm_vcpu_ioctl(CPU(cpu), type, xsave);
if (ret < 0) {
return ret;
}
diff --git a/target/i386/xsave_helper.c b/target/i386/xsave_helper.c
index ac61a96344..c3d2c9e43c 100644
--- a/target/i386/xsave_helper.c
+++ b/target/i386/xsave_helper.c
@@ -5,6 +5,7 @@
#include "qemu/osdep.h"
#include "cpu.h"
+#include <asm/kvm.h>
void x86_cpu_xsave_all_areas(X86CPU *cpu, void *buf, uint32_t buflen)
{
@@ -126,6 +127,23 @@ void x86_cpu_xsave_all_areas(X86CPU *cpu, void *buf,
uint32_t buflen)
memcpy(pkru, &env->pkru, sizeof(env->pkru));
}
+
+ e = &x86_ext_save_areas[XSTATE_XTILE_CFG_BIT];
+ if (e->size && e->offset) {
+ XSaveXTILECFG *tilecfg = buf + e->offset;
+
+ memcpy(tilecfg, &env->xtilecfg, sizeof(env->xtilecfg));
+ }
+
+ if (buflen > sizeof(struct kvm_xsave)) {
+ e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];
+
+ if (e->size && e->offset) {
+ XSaveXTILEDATA *tiledata = buf + e->offset;
+
+ memcpy(tiledata, &env->xtiledata, sizeof(env->xtiledata));
+ }
+ }
#endif
}
@@ -247,5 +265,22 @@ void x86_cpu_xrstor_all_areas(X86CPU *cpu, const void
*buf, uint32_t buflen)
pkru = buf + e->offset;
memcpy(&env->pkru, pkru, sizeof(env->pkru));
}
+
+ e = &x86_ext_save_areas[XSTATE_XTILE_CFG_BIT];
+ if (e->size && e->offset) {
+ const XSaveXTILECFG *tilecfg = buf + e->offset;
+
+ memcpy(&env->xtilecfg, tilecfg, sizeof(env->xtilecfg));
+ }
+
+ if (buflen > sizeof(struct kvm_xsave)) {
+ e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];
+
+ if (e->size && e->offset) {
+ const XSaveXTILEDATA *tiledata = buf + e->offset;
+
+ memcpy(&env->xtiledata, tiledata, sizeof(env->xtiledata));
+ }
+ }
#endif
}
