From 28cf1b55f346a9f56e84fa57921f5a28a99cd59b Mon Sep 17 00:00:00 2001

From: Jing Liu <jing2.liu@intel.com>

Date: Wed, 16 Feb 2022 22:04:32 -0800

Subject: [PATCH 10/24] x86: add support for KVM_CAP_XSAVE2 and AMX state

 migration

RH-Author: Paul Lai <plai@redhat.com>

RH-MergeRequest: 176: Enable KVM AMX support

RH-Commit: [10/13] d584f455ba1ecd8a4a87f3470e6aac24ba9a1f5a

RH-Bugzilla: 1916415

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Igor Mammedov <imammedo@redhat.com>

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.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.liu@intel.com>

Signed-off-by: Zeng Guang <guang.zeng@intel.com>

Signed-off-by: Wei Wang <wei.w.wang@intel.com>

Signed-off-by: Yang Zhong <yang.zhong@intel.com>

Message-Id: <20220217060434.52460-7-yang.zhong@intel.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit e56dd3c70abb31893c61ac834109fa7a38841330)

Signed-off-by: Paul Lai <plai@redhat.com>

---

 target/i386/cpu.h          |  4 ++++

 target/i386/kvm/kvm.c      | 42 ++++++++++++++++++++++++--------------

 target/i386/xsave_helper.c | 28 +++++++++++++++++++++++++

 3 files changed, 59 insertions(+), 15 deletions(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h

index f2bdef9c26..14a3501b87 100644

--- a/target/i386/cpu.h

+++ b/target/i386/cpu.h

@@ -1522,6 +1522,10 @@ 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 a64a79d870..d3d476df27 100644

--- a/target/i386/kvm/kvm.c

+++ b/target/i386/kvm/kvm.c

@@ -123,6 +123,7 @@ 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_exception_payload;

@@ -1585,6 +1586,26 @@ 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 {

@@ -1614,6 +1635,8 @@ 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;

@@ -2003,19 +2026,7 @@ 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) {

@@ -3263,13 +3274,14 @@ 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..996e9f3bfe 100644

--- a/target/i386/xsave_helper.c

+++ b/target/i386/xsave_helper.c

@@ -126,6 +126,20 @@ 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));

+    }

+

+    e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];

+    if (e->size && e->offset && buflen >= e->size + e->offset) {

+        XSaveXTILEDATA *tiledata = buf + e->offset;

+

+        memcpy(tiledata, &env->xtiledata, sizeof(env->xtiledata));

+    }

 #endif

 }

@@ -247,5 +261,19 @@ 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));

+    }

+

+    e = &x86_ext_save_areas[XSTATE_XTILE_DATA_BIT];

+    if (e->size && e->offset && buflen >= e->size + e->offset) {

+        const XSaveXTILEDATA *tiledata = buf + e->offset;

+

+        memcpy(&env->xtiledata, tiledata, sizeof(env->xtiledata));

+    }

 #endif

 }

-- 

2.35.3