Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

* Make named CPU models usable for qemu-{i386,x86_64}
* Fix backwards time with -icount auto

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# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [undefined]
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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
  target/i386: emulate 64-bit ring 0 for linux-user if LM feature is set
  target/i386: ignore CPL0-specific features in user mode emulation
  target/i386: ignore ARCH_CAPABILITIES features in user mode emulation
  target/i386: Export MSR_ARCH_CAPABILITIES bits to guests
  icount: don't adjust virtual time backwards after warp

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 101 insertions, 12 deletions

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index c0fb6b3ad9..b5688cabb4 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -623,13 +623,25 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
           CPUID_MTRR, CPUID_MCA, CPUID_CLFLUSH (needed for Win64) */
           /* missing:
           CPUID_VME, CPUID_DTS, CPUID_SS, CPUID_HT, CPUID_TM, CPUID_PBE */
+
+/*
+ * Kernel-only features that can be shown to usermode programs even if
+ * they aren't actually supported by TCG, because qemu-user only runs
+ * in CPL=3; remove them if they are ever implemented for system emulation.
+ */
+#if defined CONFIG_USER_ONLY
+#define CPUID_EXT_KERNEL_FEATURES (CPUID_EXT_PCID | CPUID_EXT_TSC_DEADLINE_TIMER | \
+                                 CPUID_EXT_X2APIC)
+#else
+#define CPUID_EXT_KERNEL_FEATURES 0
+#endif
 #define TCG_EXT_FEATURES (CPUID_EXT_SSE3 | CPUID_EXT_PCLMULQDQ | \
           CPUID_EXT_MONITOR | CPUID_EXT_SSSE3 | CPUID_EXT_CX16 | \
           CPUID_EXT_SSE41 | CPUID_EXT_SSE42 | CPUID_EXT_POPCNT | \
           CPUID_EXT_XSAVE | /* CPUID_EXT_OSXSAVE is dynamic */   \
           CPUID_EXT_MOVBE | CPUID_EXT_AES | CPUID_EXT_HYPERVISOR | \
           CPUID_EXT_RDRAND | CPUID_EXT_AVX | CPUID_EXT_F16C | \
-          CPUID_EXT_FMA)
+          CPUID_EXT_FMA | CPUID_EXT_KERNEL_FEATURES)
           /* missing:
           CPUID_EXT_DTES64, CPUID_EXT_DSCPL, CPUID_EXT_VMX, CPUID_EXT_SMX,
           CPUID_EXT_EST, CPUID_EXT_TM2, CPUID_EXT_CID,
@@ -642,22 +654,66 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
 #define TCG_EXT2_X86_64_FEATURES 0
 #endif
 
+/*
+ * CPUID_*_KERNEL_FEATURES denotes bits and features that are not usable
+ * in usermode or by 32-bit programs.  Those are added to supported
+ * TCG features unconditionally in user-mode emulation mode.  This may
+ * indeed seem strange or incorrect, but it works because code running
+ * under usermode emulation cannot access them.
+ *
+ * Even for long mode, qemu-i386 is not running "a userspace program on a
+ * 32-bit CPU"; it's running "a userspace program with a 32-bit code segment"
+ * and therefore using the 32-bit ABI; the CPU itself might be 64-bit
+ * but again the difference is only visible in kernel mode.
+ */
+#if defined CONFIG_LINUX_USER
+#define CPUID_EXT2_KERNEL_FEATURES (CPUID_EXT2_LM | CPUID_EXT2_FFXSR)
+#elif defined CONFIG_USER_ONLY
+/* FIXME: Long mode not yet supported for i386 bsd-user */
+#define CPUID_EXT2_KERNEL_FEATURES CPUID_EXT2_FFXSR
+#else
+#define CPUID_EXT2_KERNEL_FEATURES 0
+#endif
+
 #define TCG_EXT2_FEATURES ((TCG_FEATURES & CPUID_EXT2_AMD_ALIASES) | \
           CPUID_EXT2_NX | CPUID_EXT2_MMXEXT | CPUID_EXT2_RDTSCP | \
           CPUID_EXT2_3DNOW | CPUID_EXT2_3DNOWEXT | CPUID_EXT2_PDPE1GB | \
-          CPUID_EXT2_SYSCALL | TCG_EXT2_X86_64_FEATURES)
+          CPUID_EXT2_SYSCALL | TCG_EXT2_X86_64_FEATURES | \
+          CPUID_EXT2_KERNEL_FEATURES)
+
+#if defined CONFIG_USER_ONLY
+#define CPUID_EXT3_KERNEL_FEATURES CPUID_EXT3_OSVW
+#else
+#define CPUID_EXT3_KERNEL_FEATURES 0
+#endif
+
 #define TCG_EXT3_FEATURES (CPUID_EXT3_LAHF_LM | CPUID_EXT3_SVM | \
           CPUID_EXT3_CR8LEG | CPUID_EXT3_ABM | CPUID_EXT3_SSE4A | \
-          CPUID_EXT3_3DNOWPREFETCH)
+          CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_KERNEL_FEATURES)
+
 #define TCG_EXT4_FEATURES 0
+
+#if defined CONFIG_USER_ONLY
+#define CPUID_SVM_KERNEL_FEATURES (CPUID_SVM_NRIPSAVE | CPUID_SVM_VNMI)
+#else
+#define CPUID_SVM_KERNEL_FEATURES 0
+#endif
 #define TCG_SVM_FEATURES (CPUID_SVM_NPT | CPUID_SVM_VGIF | \
-          CPUID_SVM_SVME_ADDR_CHK)
+          CPUID_SVM_SVME_ADDR_CHK | CPUID_SVM_KERNEL_FEATURES)
+
 #define TCG_KVM_FEATURES 0
+
+#if defined CONFIG_USER_ONLY
+#define CPUID_7_0_EBX_KERNEL_FEATURES CPUID_7_0_EBX_INVPCID
+#else
+#define CPUID_7_0_EBX_KERNEL_FEATURES 0
+#endif
 #define TCG_7_0_EBX_FEATURES (CPUID_7_0_EBX_SMEP | CPUID_7_0_EBX_SMAP | \
           CPUID_7_0_EBX_BMI1 | CPUID_7_0_EBX_BMI2 | CPUID_7_0_EBX_ADX | \
           CPUID_7_0_EBX_PCOMMIT | CPUID_7_0_EBX_CLFLUSHOPT |            \
           CPUID_7_0_EBX_CLWB | CPUID_7_0_EBX_MPX | CPUID_7_0_EBX_FSGSBASE | \
-          CPUID_7_0_EBX_ERMS | CPUID_7_0_EBX_AVX2 | CPUID_7_0_EBX_RDSEED)
+          CPUID_7_0_EBX_ERMS | CPUID_7_0_EBX_AVX2 | CPUID_7_0_EBX_RDSEED | \
+          CPUID_7_0_EBX_KERNEL_FEATURES)
           /* missing:
           CPUID_7_0_EBX_HLE
           CPUID_7_0_EBX_INVPCID, CPUID_7_0_EBX_RTM */
@@ -672,7 +728,14 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
           CPUID_7_0_ECX_LA57 | CPUID_7_0_ECX_PKS | CPUID_7_0_ECX_VAES | \
           TCG_7_0_ECX_RDPID)
 
-#define TCG_7_0_EDX_FEATURES CPUID_7_0_EDX_FSRM
+#if defined CONFIG_USER_ONLY
+#define CPUID_7_0_EDX_KERNEL_FEATURES (CPUID_7_0_EDX_SPEC_CTRL | \
+          CPUID_7_0_EDX_ARCH_CAPABILITIES | CPUID_7_0_EDX_SPEC_CTRL_SSBD)
+#else
+#define CPUID_7_0_EDX_KERNEL_FEATURES 0
+#endif
+#define TCG_7_0_EDX_FEATURES (CPUID_7_0_EDX_FSRM | CPUID_7_0_EDX_KERNEL_FEATURES)
+
 #define TCG_7_1_EAX_FEATURES (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | \
           CPUID_7_1_EAX_FSRC)
 #define TCG_7_1_EDX_FEATURES 0
@@ -686,8 +749,17 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
 #define TCG_SGX_12_0_EBX_FEATURES 0
 #define TCG_SGX_12_1_EAX_FEATURES 0
 
+#if defined CONFIG_USER_ONLY
+#define CPUID_8000_0008_EBX_KERNEL_FEATURES (CPUID_8000_0008_EBX_IBPB | \
+          CPUID_8000_0008_EBX_IBRS | CPUID_8000_0008_EBX_STIBP | \
+          CPUID_8000_0008_EBX_STIBP_ALWAYS_ON | CPUID_8000_0008_EBX_AMD_SSBD | \
+          CPUID_8000_0008_EBX_AMD_PSFD)
+#else
+#define CPUID_8000_0008_EBX_KERNEL_FEATURES 0
+#endif
+
 #define TCG_8000_0008_EBX  (CPUID_8000_0008_EBX_XSAVEERPTR | \
-          CPUID_8000_0008_EBX_WBNOINVD)
+          CPUID_8000_0008_EBX_WBNOINVD | CPUID_8000_0008_EBX_KERNEL_FEATURES)
 
 FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
     [FEAT_1_EDX] = {
@@ -1060,15 +1132,22 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             "rdctl-no", "ibrs-all", "rsba", "skip-l1dfl-vmentry",
             "ssb-no", "mds-no", "pschange-mc-no", "tsx-ctrl",
             "taa-no", NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
             NULL, "fb-clear", NULL, NULL,
             NULL, NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            "pbrsb-no", NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
         },
         .msr = {
             .index = MSR_IA32_ARCH_CAPABILITIES,
         },
+        /*
+         * FEAT_ARCH_CAPABILITIES only affects a read-only MSR, which
+         * cannot be read from user mode.  Therefore, it has no impact
+         > on any user-mode operation, and warnings about unsupported
+         * features do not matter.
+         */
+        .tcg_features = ~0U,
     },
     [FEAT_CORE_CAPABILITY] = {
         .type = MSR_FEATURE_WORD,
@@ -5463,7 +5542,15 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
     }
 #ifndef TARGET_X86_64
     if (w == FEAT_8000_0001_EDX) {
-        r &= ~CPUID_EXT2_LM;
+        /*
+         * 32-bit TCG can emulate 64-bit compatibility mode.  If there is no
+         * way for userspace to get out of its 32-bit jail, we can leave
+         * the LM bit set.
+         */
+        uint32_t unavail = tcg_enabled()
+            ? CPUID_EXT2_LM & ~CPUID_EXT2_KERNEL_FEATURES
+            : CPUID_EXT2_LM;
+        r &= ~unavail;
     }
 #endif
     if (migratable_only) {
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 28cb3fb7f4..90c7b32f36 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -173,12 +173,14 @@ typedef struct DisasContext {
 #endif
 #if !defined(TARGET_X86_64)
 #define CODE64(S) false
-#define LMA(S)    false
 #elif defined(CONFIG_USER_ONLY)
 #define CODE64(S) true
-#define LMA(S)    true
 #else
 #define CODE64(S) (((S)->flags & HF_CS64_MASK) != 0)
+#endif
+#if defined(CONFIG_SOFTMMU) && !defined(TARGET_X86_64)
+#define LMA(S)    false
+#else
 #define LMA(S)    (((S)->flags & HF_LMA_MASK) != 0)
 #endif