From 8a8d1ef278933a3c3a11f8d8c2985e0af71741b4 Mon Sep 17 00:00:00 2001

From: David Edmondson <david.edmondson@oracle.com>

Date: Mon, 5 Jul 2021 11:46:28 +0100

Subject: [PATCH 4/7] target/i386: Pass buffer and length to XSAVE helper

RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>

RH-MergeRequest: 113: non-av 8.5z: Fix XSAVE on newer CPUs

RH-Commit: [4/7] 77e093a6ed3928b9191b37faad3cb50b4bdd65e3

RH-Bugzilla: 2065239

RH-Acked-by: Jon Maloy <jmaloy@redhat.com>

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

RH-Acked-by: Bandan Das <None>

In preparation for removing assumptions about XSAVE area offsets, pass

a buffer pointer and buffer length to the XSAVE helper functions.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>

Message-Id: <20210705104632.2902400-5-david.edmondson@oracle.com>

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

(cherry picked from commit c0198c5f87b6db25712672292e01ab710d6ef631)

  dgilbert: Manual merge in target/i386/hvf/x86hvf.c

---

 target/i386/cpu.h          |  5 +++--

 target/i386/hvf/hvf.c      |  3 ++-

 target/i386/hvf/x86hvf.c   | 19 ++++++++-----------

 target/i386/kvm.c          | 13 +++++++------

 target/i386/xsave_helper.c | 17 +++++++++--------

 5 files changed, 29 insertions(+), 28 deletions(-)

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

index d586b5508d..8daa83a6a3 100644

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

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

@@ -1626,6 +1626,7 @@ typedef struct CPUX86State {

     int64_t user_tsc_khz; /* for sanity check only */

 #if defined(CONFIG_KVM) || defined(CONFIG_HVF)

     void *xsave_buf;

+    uint32_t xsave_buf_len;

 #endif

 #if defined(CONFIG_KVM)

     struct kvm_nested_state *nested_state;

@@ -2254,8 +2255,8 @@ void x86_cpu_dump_local_apic_state(CPUState *cs, int flags);

 /* cpu.c */

 bool cpu_is_bsp(X86CPU *cpu);

-void x86_cpu_xrstor_all_areas(X86CPU *cpu, const X86XSaveArea *buf);

-void x86_cpu_xsave_all_areas(X86CPU *cpu, X86XSaveArea *buf);

+void x86_cpu_xrstor_all_areas(X86CPU *cpu, const void *buf, uint32_t buflen);

+void x86_cpu_xsave_all_areas(X86CPU *cpu, void *buf, uint32_t buflen);

 void x86_update_hflags(CPUX86State* env);

 static inline bool hyperv_feat_enabled(X86CPU *cpu, int feat)

diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c

index d72543dc31..bbede52fb7 100644

--- a/target/i386/hvf/hvf.c

+++ b/target/i386/hvf/hvf.c

@@ -609,7 +609,8 @@ int hvf_init_vcpu(CPUState *cpu)

     wvmcs(cpu->hvf_fd, VMCS_TPR_THRESHOLD, 0);

     x86cpu = X86_CPU(cpu);

-    x86cpu->env.xsave_buf = qemu_memalign(4096, 4096);

+    x86cpu->env.xsave_buf_len = 4096;

+    x86cpu->env.xsave_buf = qemu_memalign(4096, x86cpu->env.xsave_buf_len);

     hv_vcpu_enable_native_msr(cpu->hvf_fd, MSR_STAR, 1);

     hv_vcpu_enable_native_msr(cpu->hvf_fd, MSR_LSTAR, 1);

diff --git a/target/i386/hvf/x86hvf.c b/target/i386/hvf/x86hvf.c

index edefe5319a..7be0582f28 100644

--- a/target/i386/hvf/x86hvf.c

+++ b/target/i386/hvf/x86hvf.c

@@ -72,14 +72,12 @@ void hvf_get_segment(SegmentCache *qseg, struct vmx_segment *vmx_seg)

 void hvf_put_xsave(CPUState *cpu_state)

 {

+    void *xsave = X86_CPU(cpu_state)->env.xsave_buf;

+    uint32_t xsave_len = X86_CPU(cpu_state)->env.xsave_buf_len;

-    struct X86XSaveArea *xsave;

+    x86_cpu_xsave_all_areas(X86_CPU(cpu_state), xsave, xsave_len);

-    xsave = X86_CPU(cpu_state)->env.xsave_buf;

-

-    x86_cpu_xsave_all_areas(X86_CPU(cpu_state), xsave);

-

-    if (hv_vcpu_write_fpstate(cpu_state->hvf_fd, (void*)xsave, 4096)) {

+    if (hv_vcpu_write_fpstate(cpu_state->hvf_fd, xsave, xsave_len)) {

         abort();

     }

 }

@@ -157,15 +155,14 @@ void hvf_put_msrs(CPUState *cpu_state)

 void hvf_get_xsave(CPUState *cpu_state)

 {

-    struct X86XSaveArea *xsave;

-

-    xsave = X86_CPU(cpu_state)->env.xsave_buf;

+    void *xsave = X86_CPU(cpu_state)->env.xsave_buf;

+    uint32_t xsave_len = X86_CPU(cpu_state)->env.xsave_buf_len;

-    if (hv_vcpu_read_fpstate(cpu_state->hvf_fd, (void*)xsave, 4096)) {

+    if (hv_vcpu_read_fpstate(cpu_state->hvf_fd, xsave, xsave_len)) {

         abort();

     }

-    x86_cpu_xrstor_all_areas(X86_CPU(cpu_state), xsave);

+    x86_cpu_xrstor_all_areas(X86_CPU(cpu_state), xsave, xsave_len);

 }

 void hvf_get_segments(CPUState *cpu_state)

diff --git a/target/i386/kvm.c b/target/i386/kvm.c

index 215487b17d..8167587445 100644

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

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

@@ -1826,8 +1826,9 @@ int kvm_arch_init_vcpu(CPUState *cs)

     }

     if (has_xsave) {

-        env->xsave_buf = qemu_memalign(4096, sizeof(struct kvm_xsave));

-        memset(env->xsave_buf, 0, sizeof(struct kvm_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);

     }

     max_nested_state_len = kvm_max_nested_state_length();

@@ -2353,12 +2354,12 @@ static int kvm_put_fpu(X86CPU *cpu)

 static int kvm_put_xsave(X86CPU *cpu)

 {

     CPUX86State *env = &cpu->env;

-    X86XSaveArea *xsave = env->xsave_buf;

+    void *xsave = env->xsave_buf;

     if (!has_xsave) {

         return kvm_put_fpu(cpu);

     }

-    x86_cpu_xsave_all_areas(cpu, xsave);

+    x86_cpu_xsave_all_areas(cpu, xsave, env->xsave_buf_len);

     return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_XSAVE, xsave);

 }

@@ -2977,7 +2978,7 @@ static int kvm_get_fpu(X86CPU *cpu)

 static int kvm_get_xsave(X86CPU *cpu)

 {

     CPUX86State *env = &cpu->env;

-    X86XSaveArea *xsave = env->xsave_buf;

+    void *xsave = env->xsave_buf;

     int ret;

     if (!has_xsave) {

@@ -2988,7 +2989,7 @@ static int kvm_get_xsave(X86CPU *cpu)

     if (ret < 0) {

         return ret;

     }

-    x86_cpu_xrstor_all_areas(cpu, xsave);

+    x86_cpu_xrstor_all_areas(cpu, xsave, env->xsave_buf_len);

     return 0;

 }

diff --git a/target/i386/xsave_helper.c b/target/i386/xsave_helper.c

index 818115e7d2..b16c6ac0fe 100644

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

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

@@ -6,14 +6,16 @@

 #include "cpu.h"

-void x86_cpu_xsave_all_areas(X86CPU *cpu, X86XSaveArea *buf)

+void x86_cpu_xsave_all_areas(X86CPU *cpu, void *buf, uint32_t buflen)

 {

     CPUX86State *env = &cpu->env;

     X86XSaveArea *xsave = buf;

-

     uint16_t cwd, swd, twd;

     int i;

-    memset(xsave, 0, sizeof(X86XSaveArea));

+

+    assert(buflen >= sizeof(*xsave));

+

+    memset(xsave, 0, buflen);

     twd = 0;

     swd = env->fpus & ~(7 << 11);

     swd |= (env->fpstt & 7) << 11;

@@ -56,17 +58,17 @@ void x86_cpu_xsave_all_areas(X86CPU *cpu, X86XSaveArea *buf)

             16 * sizeof env->xmm_regs[16]);

     memcpy(&xsave->pkru_state, &env->pkru, sizeof env->pkru);

 #endif

-

 }

-void x86_cpu_xrstor_all_areas(X86CPU *cpu, const X86XSaveArea *buf)

+void x86_cpu_xrstor_all_areas(X86CPU *cpu, const void *buf, uint32_t buflen)

 {

-

     CPUX86State *env = &cpu->env;

     const X86XSaveArea *xsave = buf;

-

     int i;

     uint16_t cwd, swd, twd;

+

+    assert(buflen >= sizeof(*xsave));

+

     cwd = xsave->legacy.fcw;

     swd = xsave->legacy.fsw;

     twd = xsave->legacy.ftw;

@@ -108,5 +110,4 @@ void x86_cpu_xrstor_all_areas(X86CPU *cpu, const X86XSaveArea *buf)

            16 * sizeof env->xmm_regs[16]);

     memcpy(&env->pkru, &xsave->pkru_state, sizeof env->pkru);

 #endif

-

 }

-- 

2.27.0