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envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add support for saving/restoring extended save states when signals are delivered. This allows using AVX, MPX or PKRU registers in signal handlers. Reviewed-by: Richard Henderson Signed-off-by: Paolo Bonzini --- linux-user/i386/signal.c | 119 +++++++++++++++++++++++++++++------ target/i386/cpu.c | 2 +- target/i386/cpu.h | 3 + target/i386/tcg/fpu_helper.c | 64 +++++++++++-------- 4 files changed, 142 insertions(+), 46 deletions(-) diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 58b11be116..60fa07d6f9 100644 --- a/linux-user/i386/signal.c +++ b/linux-user/i386/signal.c @@ -24,6 +24,10 @@ /* from the Linux kernel - /arch/x86/include/uapi/asm/sigcontext.h */ +#define TARGET_FP_XSTATE_MAGIC1 0x46505853U /* FPXS */ +#define TARGET_FP_XSTATE_MAGIC2 0x46505845U /* FPXE */ +#define TARGET_FP_XSTATE_MAGIC2_SIZE 4 + struct target_fpreg { uint16_t significand[4]; uint16_t exponent; @@ -39,6 +43,15 @@ struct target_xmmreg { uint32_t element[4]; }; +struct target_fpx_sw_bytes { + uint32_t magic1; + uint32_t extended_size; + uint64_t xfeatures; + uint32_t xstate_size; + uint32_t reserved[7]; +}; +QEMU_BUILD_BUG_ON(sizeof(struct target_fpx_sw_bytes) != 12*4); + struct target_fpstate_fxsave { /* FXSAVE format */ uint16_t cw; @@ -51,10 +64,13 @@ struct target_fpstate_fxsave { uint32_t mxcsr_mask; uint32_t st_space[32]; uint32_t xmm_space[64]; - uint32_t reserved[24]; + uint32_t hw_reserved[12]; + struct target_fpx_sw_bytes sw_reserved; + uint8_t xfeatures[]; }; #define TARGET_FXSAVE_SIZE sizeof(struct target_fpstate_fxsave) QEMU_BUILD_BUG_ON(TARGET_FXSAVE_SIZE != 512); +QEMU_BUILD_BUG_ON(offsetof(struct target_fpstate_fxsave, sw_reserved) != 464); struct target_fpstate_32 { /* Regular FPU environment */ @@ -214,13 +230,39 @@ struct rt_sigframe { * Set up a signal frame. */ -static void fxsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, - abi_ulong fxsave_addr) +static void xsave_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, + abi_ulong fxsave_addr) { - /* fxsave_addr must be 16 byte aligned for fxsave */ - assert(!(fxsave_addr & 0xf)); + if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { + /* fxsave_addr must be 16 byte aligned for fxsave */ + assert(!(fxsave_addr & 0xf)); - cpu_x86_fxsave(env, fxsave_addr); + cpu_x86_fxsave(env, fxsave_addr); + __put_user(0, &fxsave->sw_reserved.magic1); + } else { + uint32_t xstate_size = xsave_area_size(env->xcr0, false); + uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE; + + /* + * extended_size is the offset from fpstate_addr to right after the end + * of the extended save states. On 32-bit that includes the legacy + * FSAVE area. + */ + uint32_t extended_size = TARGET_FPSTATE_FXSAVE_OFFSET + + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE; + + /* fxsave_addr must be 64 byte aligned for xsave */ + assert(!(fxsave_addr & 0x3f)); + + /* Zero the header, XSAVE *adds* features to an existing save state. */ + memset(fxsave->xfeatures, 0, 64); + cpu_x86_xsave(env, fxsave_addr); + __put_user(TARGET_FP_XSTATE_MAGIC1, &fxsave->sw_reserved.magic1); + __put_user(extended_size, &fxsave->sw_reserved.extended_size); + __put_user(env->xcr0, &fxsave->sw_reserved.xfeatures); + __put_user(xstate_size, &fxsave->sw_reserved.xstate_size); + __put_user(TARGET_FP_XSTATE_MAGIC2, (uint32_t *) &fxsave->xfeatures[xfeatures_size]); + } } static void setup_sigcontext(struct target_sigcontext *sc, @@ -257,8 +299,8 @@ static void setup_sigcontext(struct target_sigcontext *sc, if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { magic = 0xffff; } else { - fxsave_sigcontext(env, &fpstate->fxsave, - fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET); + xsave_sigcontext(env, &fpstate->fxsave, + fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET); magic = 0; } __put_user(magic, &fpstate->magic); @@ -291,7 +333,7 @@ static void setup_sigcontext(struct target_sigcontext *sc, __put_user((uint16_t)0, &sc->fs); __put_user(env->segs[R_SS].selector, &sc->ss); - fxsave_sigcontext(env, fpstate, fpstate_addr); + xsave_sigcontext(env, fpstate, fpstate_addr); #endif __put_user(fpstate_addr, &sc->fpstate); @@ -332,8 +374,12 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t fxsave_offset if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { return (esp - (fxsave_offset + TARGET_FXSAVE_SIZE)) & -8ul; - } else { + } else if (!(env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE)) { return ((esp - TARGET_FXSAVE_SIZE) & -16ul) - fxsave_offset; + } else { + size_t xstate_size = + xsave_area_size(env->xcr0, false) + TARGET_FP_XSTATE_MAGIC2_SIZE; + return ((esp - xstate_size) & -64ul) - fxsave_offset; } } @@ -437,7 +483,11 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, } /* Create the ucontext. */ - __put_user(0, &frame->uc.tuc_flags); + if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { + __put_user(1, &frame->uc.tuc_flags); + } else { + __put_user(0, &frame->uc.tuc_flags); + } __put_user(0, &frame->uc.tuc_link); target_save_altstack(&frame->uc.tuc_stack, env); setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env, @@ -491,10 +541,37 @@ give_sigsegv: force_sigsegv(sig); } +static int xrstor_sigcontext(CPUX86State *env, struct target_fpstate_fxsave *fxsave, + abi_ulong fxsave_addr) +{ + if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) { + uint32_t extended_size = tswapl(fxsave->sw_reserved.extended_size); + uint32_t xstate_size = tswapl(fxsave->sw_reserved.xstate_size); + uint32_t xfeatures_size = xstate_size - TARGET_FXSAVE_SIZE; + + /* Linux checks MAGIC2 using xstate_size, not extended_size. */ + if (tswapl(fxsave->sw_reserved.magic1) == TARGET_FP_XSTATE_MAGIC1 && + extended_size >= TARGET_FPSTATE_FXSAVE_OFFSET + xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE) { + if (!access_ok(env_cpu(env), VERIFY_READ, fxsave_addr, + extended_size - TARGET_FPSTATE_FXSAVE_OFFSET)) { + return 1; + } + if (tswapl(*(uint32_t *) &fxsave->xfeatures[xfeatures_size]) == TARGET_FP_XSTATE_MAGIC2) { + cpu_x86_xrstor(env, fxsave_addr); + return 0; + } + } + /* fall through to fxrstor */ + } + + cpu_x86_fxrstor(env, fxsave_addr); + return 0; +} + static int restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc) { - unsigned int err = 0; + int err = 1; abi_ulong fpstate_addr; unsigned int tmpflags; @@ -545,24 +622,28 @@ restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc) fpstate_addr = tswapl(sc->fpstate); if (fpstate_addr != 0) { - if (!access_ok(env_cpu(env), VERIFY_READ, fpstate_addr, - sizeof(struct target_fpstate))) { - goto badframe; + struct target_fpstate *fpstate; + if (!lock_user_struct(VERIFY_READ, fpstate, fpstate_addr, + sizeof(struct target_fpstate))) { + return err; } #ifndef TARGET_X86_64 if (!(env->features[FEAT_1_EDX] & CPUID_FXSR)) { cpu_x86_frstor(env, fpstate_addr, 1); + err = 0; } else { - cpu_x86_fxrstor(env, fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET); + err = xrstor_sigcontext(env, &fpstate->fxsave, + fpstate_addr + TARGET_FPSTATE_FXSAVE_OFFSET); } #else - cpu_x86_fxrstor(env, fpstate_addr); + err = xrstor_sigcontext(env, fpstate, fpstate_addr); #endif + unlock_user_struct(fpstate, fpstate_addr, 0); + } else { + err = 0; } return err; -badframe: - return 1; } /* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */ diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 06884177fa..8a11470507 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1467,7 +1467,7 @@ ExtSaveArea x86_ext_save_areas[XSAVE_STATE_AREA_COUNT] = { }, }; -static uint32_t xsave_area_size(uint64_t mask, bool compacted) +uint32_t xsave_area_size(uint64_t mask, bool compacted) { uint64_t ret = x86_ext_save_areas[0].size; const ExtSaveArea *esa; diff --git a/target/i386/cpu.h b/target/i386/cpu.h index d4124973ce..9327353fff 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -2071,6 +2071,8 @@ void cpu_x86_fsave(CPUX86State *s, target_ulong ptr, int data32); void cpu_x86_frstor(CPUX86State *s, target_ulong ptr, int data32); void cpu_x86_fxsave(CPUX86State *s, target_ulong ptr); void cpu_x86_fxrstor(CPUX86State *s, target_ulong ptr); +void cpu_x86_xsave(CPUX86State *s, target_ulong ptr); +void cpu_x86_xrstor(CPUX86State *s, target_ulong ptr); /* cpu.c */ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1, @@ -2327,6 +2329,7 @@ bool cpu_is_bsp(X86CPU *cpu); 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); +uint32_t xsave_area_size(uint64_t mask, bool compacted); void x86_update_hflags(CPUX86State* env); static inline bool hyperv_feat_enabled(X86CPU *cpu, int feat) diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c index 30bc44fcf8..ad58931751 100644 --- a/target/i386/tcg/fpu_helper.c +++ b/target/i386/tcg/fpu_helper.c @@ -2502,18 +2502,6 @@ void helper_frstor(CPUX86State *env, target_ulong ptr, int data32) do_frstor(env, ptr, data32, GETPC()); } -#if defined(CONFIG_USER_ONLY) -void cpu_x86_fsave(CPUX86State *env, target_ulong ptr, int data32) -{ - do_fsave(env, ptr, data32, 0); -} - -void cpu_x86_frstor(CPUX86State *env, target_ulong ptr, int data32) -{ - do_frstor(env, ptr, data32, 0); -} -#endif - #define XO(X) offsetof(X86XSaveArea, X) static void do_xsave_fpu(CPUX86State *env, target_ulong ptr, uintptr_t ra) @@ -2787,21 +2775,8 @@ void helper_fxrstor(CPUX86State *env, target_ulong ptr) do_fxrstor(env, ptr, GETPC()); } -#if defined(CONFIG_USER_ONLY) -void cpu_x86_fxsave(CPUX86State *env, target_ulong ptr) +static void do_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm, uintptr_t ra) { - do_fxsave(env, ptr, 0); -} - -void cpu_x86_fxrstor(CPUX86State *env, target_ulong ptr) -{ - do_fxrstor(env, ptr, 0); -} -#endif - -void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm) -{ - uintptr_t ra = GETPC(); uint64_t xstate_bv, xcomp_bv, reserve0; rfbm &= env->xcr0; @@ -2894,6 +2869,43 @@ void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm) #undef XO +void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm) +{ + do_xrstor(env, ptr, rfbm, GETPC()); +} + +#if defined(CONFIG_USER_ONLY) +void cpu_x86_fsave(CPUX86State *env, target_ulong ptr, int data32) +{ + do_fsave(env, ptr, data32, 0); +} + +void cpu_x86_frstor(CPUX86State *env, target_ulong ptr, int data32) +{ + do_frstor(env, ptr, data32, 0); +} + +void cpu_x86_fxsave(CPUX86State *env, target_ulong ptr) +{ + do_fxsave(env, ptr, 0); +} + +void cpu_x86_fxrstor(CPUX86State *env, target_ulong ptr) +{ + do_fxrstor(env, ptr, 0); +} + +void cpu_x86_xsave(CPUX86State *env, target_ulong ptr) +{ + do_xsave(env, ptr, -1, get_xinuse(env), -1, 0); +} + +void cpu_x86_xrstor(CPUX86State *env, target_ulong ptr) +{ + do_xrstor(env, ptr, -1, 0); +} +#endif + uint64_t helper_xgetbv(CPUX86State *env, uint32_t ecx) { /* The OS must have enabled XSAVE. */