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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