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[73.207.178.95]) by smtp.gmail.com with ESMTPSA id v207sm2941830ywa.6.2017.02.23.21.42.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 23 Feb 2017 21:42:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Sq7iGpk9G61aW5HO9jxrPziTk6KIc6EaVIO/awdx4y8=; b=ppOU037VnacP8lznexelv0Y7BZB2RmtZngR7D4zjLpGM3xvmkiKmmokfLaBUBcKFoQ EBYuMYGv7rjgMPmB1Xx4KhyKZ5id7ng4g1gF5bIgr5UnSi+qX40igLX/u5d9hMVxgVYL eW6lBc0XF3KgsakHEU6vFs4c7jnd+Xp3t2hrhJ+CD/C37iptGFHAZqSmjVtDIt+hHE8Q E97px0tZabfP2/TCCtTqi3XzRlg/k0LlbGiQXpya7QF8SReJSpL/w7/HE21x8SIYmpBs i4n8UlOaFqiR4YVzwB3/2pWJf4uWul51wBCDiq09caQuCipWj5zo6/sTBA98yX7VshcF 8eyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Sq7iGpk9G61aW5HO9jxrPziTk6KIc6EaVIO/awdx4y8=; b=J/zsAxFuFEwyrKoRqHEvzgeKfGsSd44A8ueIOZlv4ZoipQtUugoGEMe9UkrHBsnno5 4nSIFSIiOhoOcMJxxyvXxyynSs2+Zt15PAILcl3z5d0i+F8PlxmATZTh5ya6aKToc0TU G96ZbsG27QGRUXZpoO5HNSOERbbg8TqDFskN6wFVzshJhlA3fGDQMRWwBDRnmODTFfw6 XMaRdKGkn8KuwNe7qdQVxOOBy5PR3y/tqT8Bp0NveP53I7qM4rONHHge55n3wS6c0f4d uWguafoMsJXc9H9cGjyXTxpgAqyW/gaMjy+EuqiL6r1qMkTQqJVsLW7/ZZcdvpLPaiWw pweA== X-Gm-Message-State: AMke39kpCTzCu1IXnV52RV7BZo66bLb/I/iQSoPjw04pOh2oJUCZjqexVGqllWDAttOnyw== X-Received: by 10.129.164.143 with SMTP id b137mr524908ywh.117.1487914977983; Thu, 23 Feb 2017 21:42:57 -0800 (PST) From: Pranith Kumar To: Date: Fri, 24 Feb 2017 00:42:29 -0500 Message-Id: <1487914949-1294-1-git-send-email-bobby.prani@gmail.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2607:f8b0:4002:c05::241 Subject: [Qemu-devel] [PATCH v2] mttcg/i386: Patch instruction using async_safe_* framework X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , =?UTF-8?q?Alex=20Benn=C3=A9e?= , qemu-devel@nongnu.org, Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 In mttcg, calling pause_all_vcpus() during execution from the generated TBs causes a deadlock if some vCPU is waiting for exclusive execution in start_exclusive(). Fix this by using the aync_safe_* framework instead of pausing vcpus for patching instructions. CC: Richard Henderson CC: Peter Maydell CC: Alex Benn=C3=A9e Signed-off-by: Pranith Kumar Reviewed-by: Alex Benn=C3=A9e Reviewed-by: Richard Henderson --- hw/i386/kvmvapic.c | 82 ++++++++++++++++++++++++++++++++++----------------= ---- 1 file changed, 52 insertions(+), 30 deletions(-) diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c index 82a4955..11b0d49 100644 --- a/hw/i386/kvmvapic.c +++ b/hw/i386/kvmvapic.c @@ -383,8 +383,7 @@ static void patch_byte(X86CPU *cpu, target_ulong addr, = uint8_t byte) cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1); } =20 -static void patch_call(VAPICROMState *s, X86CPU *cpu, target_ulong ip, - uint32_t target) +static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target) { uint32_t offset; =20 @@ -393,23 +392,24 @@ static void patch_call(VAPICROMState *s, X86CPU *cpu,= target_ulong ip, cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset),= 1); } =20 -static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong = ip) +struct PatchInfo { + VAPICHandlers *handler; + target_ulong ip; +}; + +static void do_patch_instruction(CPUState *cs, run_on_cpu_data data) { - CPUState *cs =3D CPU(cpu); - CPUX86State *env =3D &cpu->env; - VAPICHandlers *handlers; + X86CPU *x86_cpu =3D X86_CPU(cs); + CPUX86State *env =3D &x86_cpu->env; + struct PatchInfo *info =3D (struct PatchInfo *) data.host_ptr; + VAPICHandlers *handlers =3D info->handler; + target_ulong ip =3D info->ip; uint8_t opcode[2]; uint32_t imm32 =3D 0; target_ulong current_pc =3D 0; target_ulong current_cs_base =3D 0; uint32_t current_flags =3D 0; =20 - if (smp_cpus =3D=3D 1) { - handlers =3D &s->rom_state.up; - } else { - handlers =3D &s->rom_state.mp; - } - if (!kvm_enabled()) { cpu_get_tb_cpu_state(env, ¤t_pc, ¤t_cs_base, ¤t_flags); @@ -421,48 +421,70 @@ static void patch_instruction(VAPICROMState *s, X86CP= U *cpu, target_ulong ip) } } =20 - pause_all_vcpus(); - cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0); =20 switch (opcode[0]) { case 0x89: /* mov r32 to r/m32 */ - patch_byte(cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */ - patch_call(s, cpu, ip + 1, handlers->set_tpr); + patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg= */ + patch_call(x86_cpu, ip + 1, handlers->set_tpr); break; case 0x8b: /* mov r/m32 to r32 */ - patch_byte(cpu, ip, 0x90); - patch_call(s, cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]= ); + patch_byte(x86_cpu, ip, 0x90); + patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])= ]); break; case 0xa1: /* mov abs to eax */ - patch_call(s, cpu, ip, handlers->get_tpr[0]); + patch_call(x86_cpu, ip, handlers->get_tpr[0]); break; case 0xa3: /* mov eax to abs */ - patch_call(s, cpu, ip, handlers->set_tpr_eax); + patch_call(x86_cpu, ip, handlers->set_tpr_eax); break; case 0xc7: /* mov imm32, r/m32 (c7/0) */ - patch_byte(cpu, ip, 0x68); /* push imm32 */ + patch_byte(x86_cpu, ip, 0x68); /* push imm32 */ cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0); cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1); - patch_call(s, cpu, ip + 5, handlers->set_tpr); + patch_call(x86_cpu, ip + 5, handlers->set_tpr); break; case 0xff: /* push r/m32 */ - patch_byte(cpu, ip, 0x50); /* push eax */ - patch_call(s, cpu, ip + 1, handlers->get_tpr_stack); + patch_byte(x86_cpu, ip, 0x50); /* push eax */ + patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack); break; default: abort(); } =20 - resume_all_vcpus(); + g_free(info); +} + +static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong = ip) +{ + CPUState *cs =3D CPU(cpu); + VAPICHandlers *handlers; + struct PatchInfo *info; + + if (smp_cpus =3D=3D 1) { + handlers =3D &s->rom_state.up; + } else { + handlers =3D &s->rom_state.mp; + } + + info =3D g_new(struct PatchInfo, 1); + info->handler =3D handlers; + info->ip =3D ip; =20 if (!kvm_enabled()) { - /* Both tb_lock and iothread_mutex will be reset when - * longjmps back into the cpu_exec loop. */ - tb_lock(); - tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1); - cpu_loop_exit_noexc(cs); + const run_on_cpu_func fn =3D do_patch_instruction; + + async_safe_run_on_cpu(cs, fn, RUN_ON_CPU_HOST_PTR(info)); + cs->exception_index =3D EXCP_INTERRUPT; + cpu_loop_exit(cs); } + + pause_all_vcpus(); + + do_patch_instruction(cs, RUN_ON_CPU_HOST_PTR(info)); + + resume_all_vcpus(); + g_free(info); } =20 void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong = ip, --=20 2.7.4