[Qemu-devel] [PULL 29/29] target-i386: implement PKE for TCG

[Paolo Bonzini <pbonzini@redhat.com>]

Tested with kvm-unit-tests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target-i386/cpu.c         | 13 ++++++++++---
 target-i386/cpu.h         |  6 +++++-
 target-i386/fpu_helper.c  | 27 +++++++++++++++++++++++++++
 target-i386/helper.c      | 22 ++++++++++++++++++++++
 target-i386/helper.h      |  2 ++
 target-i386/misc_helper.c | 27 +++++++++++++++++++++++++++
 target-i386/translate.c   | 18 +++++++++++++++++-
 7 files changed, 110 insertions(+), 5 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index eee00d6..ddae932 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -361,7 +361,7 @@ static const char *cpuid_6_feature_name[] = {
           CPUID_7_0_EBX_HLE, CPUID_7_0_EBX_AVX2,
           CPUID_7_0_EBX_ERMS, CPUID_7_0_EBX_INVPCID, CPUID_7_0_EBX_RTM,
           CPUID_7_0_EBX_RDSEED */
-#define TCG_7_0_ECX_FEATURES 0
+#define TCG_7_0_ECX_FEATURES (CPUID_7_0_ECX_PKU | CPUID_7_0_ECX_OSPKE)
 #define TCG_APM_FEATURES 0
 #define TCG_6_EAX_FEATURES CPUID_6_EAX_ARAT
 #define TCG_XSAVE_FEATURES (CPUID_XSAVE_XSAVEOPT | CPUID_XSAVE_XGETBV1)
@@ -2426,6 +2426,9 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             *eax = 0; /* Maximum ECX value for sub-leaves */
             *ebx = env->features[FEAT_7_0_EBX]; /* Feature flags */
             *ecx = env->features[FEAT_7_0_ECX]; /* Feature flags */
+            if ((*ecx & CPUID_7_0_ECX_PKU) && env->cr[4] & CR4_PKE_MASK) {
+                *ecx |= CPUID_7_0_ECX_OSPKE;
+            }
             *edx = 0; /* Reserved */
         } else {
             *eax = 0;
@@ -2733,9 +2736,13 @@ static void x86_cpu_reset(CPUState *s)
     if (env->features[FEAT_1_EDX] & CPUID_SSE) {
         xcr0 |= XSTATE_SSE_MASK;
     }
-    if (env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_MPX) {
-        xcr0 |= XSTATE_BNDREGS_MASK | XSTATE_BNDCSR_MASK;
+    for (i = 2; i < ARRAY_SIZE(x86_ext_save_areas); i++) {
+        const ExtSaveArea *esa = &x86_ext_save_areas[i];
+        if ((env->features[esa->feature] & esa->bits) == esa->bits) {
+            xcr0 |= 1ull << i;
+        }
     }
+
     if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
         cr4 |= CR4_OSFXSR_MASK | CR4_OSXSAVE_MASK;
     }
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 5148c82..732eb6d 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -232,6 +232,7 @@
 #define CR4_OSXSAVE_MASK (1U << 18)
 #define CR4_SMEP_MASK   (1U << 20)
 #define CR4_SMAP_MASK   (1U << 21)
+#define CR4_PKE_MASK   (1U << 22)
 
 #define DR6_BD          (1 << 13)
 #define DR6_BS          (1 << 14)
@@ -260,6 +261,7 @@
 #define PG_PSE_BIT      7
 #define PG_GLOBAL_BIT   8
 #define PG_PSE_PAT_BIT  12
+#define PG_PKRU_BIT     59
 #define PG_NX_BIT       63
 
 #define PG_PRESENT_MASK  (1 << PG_PRESENT_BIT)
@@ -275,7 +277,8 @@
 #define PG_ADDRESS_MASK  0x000ffffffffff000LL
 #define PG_HI_RSVD_MASK  (PG_ADDRESS_MASK & ~PHYS_ADDR_MASK)
 #define PG_HI_USER_MASK  0x7ff0000000000000LL
-#define PG_NX_MASK       (1LL << PG_NX_BIT)
+#define PG_PKRU_MASK     (15ULL << PG_PKRU_BIT)
+#define PG_NX_MASK       (1ULL << PG_NX_BIT)
 
 #define PG_ERROR_W_BIT     1
 
@@ -284,6 +287,7 @@
 #define PG_ERROR_U_MASK    0x04
 #define PG_ERROR_RSVD_MASK 0x08
 #define PG_ERROR_I_D_MASK  0x10
+#define PG_ERROR_PK_MASK   0x20
 
 #define MCG_CTL_P       (1ULL<<8)   /* MCG_CAP register available */
 #define MCG_SER_P       (1ULL<<24) /* MCA recovery/new status bits */
diff --git a/target-i386/fpu_helper.c b/target-i386/fpu_helper.c
index d1a7f4c..fee5573 100644
--- a/target-i386/fpu_helper.c
+++ b/target-i386/fpu_helper.c
@@ -1184,6 +1184,11 @@ static void do_xsave_bndcsr(CPUX86State *env, target_ulong addr, uintptr_t ra)
     cpu_stq_data_ra(env, addr + 8, env->bndcs_regs.sts, ra);
 }
 
+static void do_xsave_pkru(CPUX86State *env, target_ulong addr, uintptr_t ra)
+{
+    cpu_stq_data_ra(env, addr, env->pkru, ra);
+}
+
 void helper_fxsave(CPUX86State *env, target_ulong ptr)
 {
     uintptr_t ra = GETPC();
@@ -1257,6 +1262,10 @@ static void do_xsave(CPUX86State *env, target_ulong ptr, uint64_t rfbm,
         target_ulong off = x86_ext_save_areas[XSTATE_BNDCSR_BIT].offset;
         do_xsave_bndcsr(env, ptr + off, ra);
     }
+    if (opt & XSTATE_PKRU_MASK) {
+        target_ulong off = x86_ext_save_areas[XSTATE_PKRU_BIT].offset;
+        do_xsave_pkru(env, ptr + off, ra);
+    }
 
     /* Update the XSTATE_BV field.  */
     old_bv = cpu_ldq_data_ra(env, ptr + 512, ra);
@@ -1339,6 +1348,11 @@ static void do_xrstor_bndcsr(CPUX86State *env, target_ulong addr, uintptr_t ra)
     env->bndcs_regs.sts = cpu_ldq_data_ra(env, addr + 8, ra);
 }
 
+static void do_xrstor_pkru(CPUX86State *env, target_ulong addr, uintptr_t ra)
+{
+    env->pkru = cpu_ldq_data_ra(env, addr, ra);
+}
+
 void helper_fxrstor(CPUX86State *env, target_ulong ptr)
 {
     uintptr_t ra = GETPC();
@@ -1438,6 +1452,19 @@ void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm)
         }
         cpu_sync_bndcs_hflags(env);
     }
+    if (rfbm & XSTATE_PKRU_MASK) {
+        uint64_t old_pkru = env->pkru;
+        if (xstate_bv & XSTATE_PKRU_MASK) {
+            target_ulong off = x86_ext_save_areas[XSTATE_PKRU_BIT].offset;
+            do_xrstor_pkru(env, ptr + off, ra);
+        } else {
+            env->pkru = 0;
+        }
+        if (env->pkru != old_pkru) {
+            CPUState *cs = CPU(x86_env_get_cpu(env));
+            tlb_flush(cs, 1);
+        }
+    }
 }
 
 uint64_t helper_xgetbv(CPUX86State *env, uint32_t ecx)
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 3f60ec6..5755839 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -676,6 +676,10 @@ void cpu_x86_update_cr4(CPUX86State *env, uint32_t new_cr4)
         hflags |= HF_SMAP_MASK;
     }
 
+    if (!(env->features[FEAT_7_0_ECX] & CPUID_7_0_ECX_PKU)) {
+        new_cr4 &= ~CR4_PKE_MASK;
+    }
+
     env->cr[4] = new_cr4;
     env->hflags = hflags;
 
@@ -920,6 +924,24 @@ do_check_protect_pse36:
         goto do_fault_protect;
     }
 
+    if ((env->cr[4] & CR4_PKE_MASK) && (env->hflags & HF_LMA_MASK) &&
+        (ptep & PG_USER_MASK) && env->pkru) {
+        uint32_t pk = (pte & PG_PKRU_MASK) >> PG_PKRU_BIT;
+        uint32_t pkru_ad = (env->pkru >> pk * 2) & 1;
+        uint32_t pkru_wd = (env->pkru >> pk * 2) & 2;
+
+        if (pkru_ad) {
+            prot &= ~(PAGE_READ | PAGE_WRITE);
+        } else if (pkru_wd && (is_user || env->cr[0] & CR0_WP_MASK)) {
+            prot &= ~PAGE_WRITE;
+        }
+        if ((prot & (1 << is_write1)) == 0) {
+            assert(is_write1 != 2);
+            error_code |= PG_ERROR_PK_MASK;
+            goto do_fault_protect;
+        }
+    }
+
     /* yes, it can! */
     is_dirty = is_write && !(pte & PG_DIRTY_MASK);
     if (!(pte & PG_ACCESSED_MASK) || is_dirty) {
diff --git a/target-i386/helper.h b/target-i386/helper.h
index e33451a..1320edc 100644
--- a/target-i386/helper.h
+++ b/target-i386/helper.h
@@ -198,6 +198,8 @@ DEF_HELPER_FLAGS_3(xsaveopt, TCG_CALL_NO_WG, void, env, tl, i64)
 DEF_HELPER_FLAGS_3(xrstor, TCG_CALL_NO_WG, void, env, tl, i64)
 DEF_HELPER_FLAGS_2(xgetbv, TCG_CALL_NO_WG, i64, env, i32)
 DEF_HELPER_FLAGS_3(xsetbv, TCG_CALL_NO_WG, void, env, i32, i64)
+DEF_HELPER_FLAGS_2(rdpkru, TCG_CALL_NO_WG, i64, env, i32)
+DEF_HELPER_FLAGS_3(wrpkru, TCG_CALL_NO_WG, void, env, i32, i64)
 
 DEF_HELPER_FLAGS_1(clz, TCG_CALL_NO_RWG_SE, tl, tl)
 DEF_HELPER_FLAGS_1(ctz, TCG_CALL_NO_RWG_SE, tl, tl)
diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
index 5fbab8f..e31ec97 100644
--- a/target-i386/misc_helper.c
+++ b/target-i386/misc_helper.c
@@ -609,3 +609,30 @@ void helper_debug(CPUX86State *env)
     cs->exception_index = EXCP_DEBUG;
     cpu_loop_exit(cs);
 }
+
+uint64_t helper_rdpkru(CPUX86State *env, uint32_t ecx)
+{
+    if ((env->cr[4] & CR4_PKE_MASK) == 0) {
+        raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
+    }
+    if (ecx != 0) {
+        raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
+    }
+
+    return env->pkru;
+}
+
+void helper_wrpkru(CPUX86State *env, uint32_t ecx, uint64_t val)
+{
+    CPUState *cs = CPU(x86_env_get_cpu(env));
+
+    if ((env->cr[4] & CR4_PKE_MASK) == 0) {
+        raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
+    }
+    if (ecx != 0 || (val & 0xFFFFFFFF00000000ull)) {
+        raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
+    }
+
+    env->pkru = val;
+    tlb_flush(cs, 1);
+}
diff --git a/target-i386/translate.c b/target-i386/translate.c
index dd8d5cc..1a1214d 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -7322,7 +7322,23 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
             }
             gen_ldst_modrm(env, s, modrm, ot, OR_TMP0, 1);
             break;
-
+        case 0xee: /* rdpkru */
+            if (prefixes & PREFIX_LOCK) {
+                goto illegal_op;
+            }
+            tcg_gen_trunc_tl_i32(cpu_tmp2_i32, cpu_regs[R_ECX]);
+            gen_helper_rdpkru(cpu_tmp1_i64, cpu_env, cpu_tmp2_i32);
+            tcg_gen_extr_i64_tl(cpu_regs[R_EAX], cpu_regs[R_EDX], cpu_tmp1_i64);
+            break;
+        case 0xef: /* wrpkru */
+            if (prefixes & PREFIX_LOCK) {
+                goto illegal_op;
+            }
+            tcg_gen_concat_tl_i64(cpu_tmp1_i64, cpu_regs[R_EAX],
+                                  cpu_regs[R_EDX]);
+            tcg_gen_trunc_tl_i32(cpu_tmp2_i32, cpu_regs[R_ECX]);
+            gen_helper_wrpkru(cpu_env, cpu_tmp2_i32, cpu_tmp1_i64);
+            break;
         CASE_MODRM_OP(6): /* lmsw */
             if (s->cpl != 0) {
                 gen_exception(s, EXCP0D_GPF, pc_start - s->cs_base);
-- 
2.5.0