[PULL 02/21] target/i386: VMRUN and VMLOAD canonicalizations

[Paolo Bonzini]

From: Lara Lazier <laramglazier@gmail.com>

APM2 requires that VMRUN and VMLOAD canonicalize (sign extend to 63
from 48/57) all base addresses in the segment registers that have been
respectively loaded.

Signed-off-by: Lara Lazier <laramglazier@gmail.com>
Message-Id: <20210804113058.45186-1-laramglazier@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.c                   | 19 +++++++++++--------
 target/i386/cpu.h                   |  2 ++
 target/i386/tcg/sysemu/svm_helper.c | 27 +++++++++++++++++----------
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 97e250e876..fbca4e5860 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5115,6 +5115,15 @@ static void x86_register_cpudef_types(const 
X86CPUDefinition *def)
 
 }
 
+uint32_t cpu_x86_virtual_addr_width(CPUX86State *env)
+{
+    if  (env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_LA57) {
+        return 57; /* 57 bits virtual */
+    } else {
+        return 48; /* 48 bits virtual */
+    }
+}
+
 void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
                    uint32_t *eax, uint32_t *ebx,
                    uint32_t *ecx, uint32_t *edx)
@@ -5517,16 +5526,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
         break;
     case 0x80000008:
         /* virtual & phys address size in low 2 bytes. */
+        *eax = cpu->phys_bits;
         if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
             /* 64 bit processor */
-            *eax = cpu->phys_bits; /* configurable physical bits */
-            if  (env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_LA57) {
-                *eax |= 0x00003900; /* 57 bits virtual */
-            } else {
-                *eax |= 0x00003000; /* 48 bits virtual */
-            }
-        } else {
-            *eax = cpu->phys_bits;
+             *eax |= (cpu_x86_virtual_addr_width(env) << 8);
         }
         *ebx = env->features[FEAT_8000_0008_EBX];
         if (cs->nr_cores * cs->nr_threads > 1) {
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 21b33fbe2e..aafc2eb696 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1955,6 +1955,8 @@ typedef struct PropValue {
 } PropValue;
 void x86_cpu_apply_props(X86CPU *cpu, PropValue *props);
 
+uint32_t cpu_x86_virtual_addr_width(CPUX86State *env);
+
 /* cpu.c other functions (cpuid) */
 void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
                    uint32_t *eax, uint32_t *ebx,
diff --git a/target/i386/tcg/sysemu/svm_helper.c 
b/target/i386/tcg/sysemu/svm_helper.c
index 0d549b3d6c..0e7de4e054 100644
--- a/target/i386/tcg/sysemu/svm_helper.c
+++ b/target/i386/tcg/sysemu/svm_helper.c
@@ -41,6 +41,16 @@ static inline void svm_save_seg(CPUX86State *env, hwaddr 
addr,
              ((sc->flags >> 8) & 0xff) | ((sc->flags >> 12) & 0x0f00));
 }
 
+/*
+ * VMRUN and VMLOAD canonicalizes (i.e., sign-extend to bit 63) all base
+ * addresses in the segment registers that have been loaded.
+ */
+static inline void svm_canonicalization(CPUX86State *env, target_ulong 
*seg_base)
+{
+    uint16_t shift_amt = 64 - cpu_x86_virtual_addr_width(env);
+    *seg_base = ((((long) *seg_base) << shift_amt) >> shift_amt);
+}
+
 static inline void svm_load_seg(CPUX86State *env, hwaddr addr,
                                 SegmentCache *sc)
 {
@@ -53,6 +63,7 @@ static inline void svm_load_seg(CPUX86State *env, hwaddr addr,
     sc->limit = x86_ldl_phys(cs, addr + offsetof(struct vmcb_seg, limit));
     flags = x86_lduw_phys(cs, addr + offsetof(struct vmcb_seg, attrib));
     sc->flags = ((flags & 0xff) << 8) | ((flags & 0x0f00) << 12);
+    svm_canonicalization(env, &sc->base);
 }
 
 static inline void svm_load_seg_cache(CPUX86State *env, hwaddr addr,
@@ -245,16 +256,6 @@ void helper_vmrun(CPUX86State *env, int aflag, int 
next_eip_addend)
     env->tsc_offset = x86_ldq_phys(cs, env->vm_vmcb +
                                offsetof(struct vmcb, control.tsc_offset));
 
-    env->gdt.base  = x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
-                                                      save.gdtr.base));
-    env->gdt.limit = x86_ldl_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
-                                                      save.gdtr.limit));
-
-    env->idt.base  = x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
-                                                      save.idtr.base));
-    env->idt.limit = x86_ldl_phys(cs, env->vm_vmcb + offsetof(struct vmcb,
-                                                      save.idtr.limit));
-
     new_cr0 = x86_ldq_phys(cs, env->vm_vmcb + offsetof(struct vmcb, save.cr0));
     if (new_cr0 & SVM_CR0_RESERVED_MASK) {
         cpu_vmexit(env, SVM_EXIT_ERR, 0, GETPC());
@@ -308,6 +309,10 @@ void helper_vmrun(CPUX86State *env, int aflag, int 
next_eip_addend)
                        R_SS);
     svm_load_seg_cache(env, env->vm_vmcb + offsetof(struct vmcb, save.ds),
                        R_DS);
+    svm_load_seg(env, env->vm_vmcb + offsetof(struct vmcb, save.idtr),
+                       &env->idt);
+    svm_load_seg(env, env->vm_vmcb + offsetof(struct vmcb, save.gdtr),
+                       &env->gdt);
 
     env->eip = x86_ldq_phys(cs,
                         env->vm_vmcb + offsetof(struct vmcb, save.rip));
@@ -446,6 +451,7 @@ void helper_vmload(CPUX86State *env, int aflag)
     env->lstar = x86_ldq_phys(cs, addr + offsetof(struct vmcb, save.lstar));
     env->cstar = x86_ldq_phys(cs, addr + offsetof(struct vmcb, save.cstar));
     env->fmask = x86_ldq_phys(cs, addr + offsetof(struct vmcb, save.sfmask));
+    svm_canonicalization(env, &env->kernelgsbase);
 #endif
     env->star = x86_ldq_phys(cs, addr + offsetof(struct vmcb, save.star));
     env->sysenter_cs = x86_ldq_phys(cs,
@@ -454,6 +460,7 @@ void helper_vmload(CPUX86State *env, int aflag)
                                                  save.sysenter_esp));
     env->sysenter_eip = x86_ldq_phys(cs, addr + offsetof(struct vmcb,
                                                  save.sysenter_eip));
+
 }
 
 void helper_vmsave(CPUX86State *env, int aflag)
-- 
2.31.1