From patchwork Tue Jul 30 07:57:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibo Mao X-Patchwork-Id: 13746894 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9A81A191F7B; Tue, 30 Jul 2024 07:57:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722326268; cv=none; b=GkpXZjKb7lkyLr7VAAA0LoKMXf6a/98QQAk4VY35QZPjLtZe8gZdT+GMA/ulJtiMq2+UjIjYPu0m6O2ojEH7IJILufOoAvCQNAXBcQZvENsPKREUYNwkDG72ODfA5QnkBgyY5w0acLvqaZ2DwM2Ll3kdBQyex/jQ3GMKndYry64= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722326268; c=relaxed/simple; bh=9wMZqdqGzCugtv9QYM7E5DR7ZJHLVgka004bdRgej40=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=mZXbPVYQA33H4CbFTXT1c96NGF4aS2dtTkhLxvRbaQSiDJVwbHF7TySlWUg1CekdCJlsk8qxv2G9Fkc6cO7SzzfhN2eYKLqm2esT0HX5sVUXvBNaKOI3beNGREfK8O6INCZfBCsg7LWO/IesqzOB2ULRStN1604uTVfp5qAFPV8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [10.2.5.213]) by gateway (Coremail) with SMTP id _____8Cx+en5nKhm91EEAA--.14911S3; Tue, 30 Jul 2024 15:57:45 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.213]) by front1 (Coremail) with SMTP id qMiowMAxX8f4nKhmrTUGAA--.30670S3; Tue, 30 Jul 2024 15:57:44 +0800 (CST) From: Bibo Mao To: Tianrui Zhao , Huacai Chen Cc: WANG Xuerui , kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, Jiaxun Yang Subject: [PATCH v6 1/3] LoongArch: KVM: Add HW Binary Translation extension support Date: Tue, 30 Jul 2024 15:57:41 +0800 Message-Id: <20240730075744.1215856-2-maobibo@loongson.cn> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20240730075744.1215856-1-maobibo@loongson.cn> References: <20240730075744.1215856-1-maobibo@loongson.cn> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: qMiowMAxX8f4nKhmrTUGAA--.30670S3 X-CM-SenderInfo: xpdruxter6z05rqj20fqof0/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Loongson Binary Translation (LBT) is used to accelerate binary translation, which contains 4 scratch registers (scr0 to scr3), x86/ARM eflags (eflags) and x87 fpu stack pointer (ftop). Like FPU extension, here late enabling method is used for LBT. LBT context is saved/restored on vcpu context switch path. Signed-off-by: Bibo Mao --- arch/loongarch/include/asm/kvm_host.h | 8 ++++ arch/loongarch/include/asm/kvm_vcpu.h | 6 +++ arch/loongarch/kvm/exit.c | 9 ++++ arch/loongarch/kvm/vcpu.c | 66 ++++++++++++++++++++++++++- 4 files changed, 88 insertions(+), 1 deletion(-) diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h index 44b54965f5b4..c409ab15bae1 100644 --- a/arch/loongarch/include/asm/kvm_host.h +++ b/arch/loongarch/include/asm/kvm_host.h @@ -137,6 +137,7 @@ enum emulation_result { #define KVM_LARCH_LASX (0x1 << 2) #define KVM_LARCH_SWCSR_LATEST (0x1 << 3) #define KVM_LARCH_HWCSR_USABLE (0x1 << 4) +#define KVM_LARCH_LBT (0x1 << 5) struct kvm_vcpu_arch { /* @@ -170,6 +171,7 @@ struct kvm_vcpu_arch { /* FPU state */ struct loongarch_fpu fpu FPU_ALIGN; + struct loongarch_lbt lbt; /* CSR state */ struct loongarch_csrs *csr; @@ -241,6 +243,12 @@ static inline bool kvm_guest_has_lasx(struct kvm_vcpu_arch *arch) return arch->cpucfg[2] & CPUCFG2_LASX; } +static inline bool kvm_guest_has_lbt(struct kvm_vcpu_arch *arch) +{ + return arch->cpucfg[2] & (CPUCFG2_X86BT | CPUCFG2_ARMBT + | CPUCFG2_MIPSBT); +} + /* Debug: dump vcpu state */ int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu); diff --git a/arch/loongarch/include/asm/kvm_vcpu.h b/arch/loongarch/include/asm/kvm_vcpu.h index c416cb7125c0..3cc906a0ff54 100644 --- a/arch/loongarch/include/asm/kvm_vcpu.h +++ b/arch/loongarch/include/asm/kvm_vcpu.h @@ -75,6 +75,12 @@ static inline void kvm_save_lasx(struct loongarch_fpu *fpu) { } static inline void kvm_restore_lasx(struct loongarch_fpu *fpu) { } #endif +#ifdef CONFIG_CPU_HAS_LBT +int kvm_own_lbt(struct kvm_vcpu *vcpu); +#else +static inline int kvm_own_lbt(struct kvm_vcpu *vcpu) { return -EINVAL; } +#endif + void kvm_init_timer(struct kvm_vcpu *vcpu, unsigned long hz); void kvm_reset_timer(struct kvm_vcpu *vcpu); void kvm_save_timer(struct kvm_vcpu *vcpu); diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index ea73f9dc2cc6..be2c326253a3 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -835,6 +835,14 @@ static int kvm_handle_hypercall(struct kvm_vcpu *vcpu) return ret; } +static int kvm_handle_lbt_disabled(struct kvm_vcpu *vcpu) +{ + if (kvm_own_lbt(vcpu)) + kvm_queue_exception(vcpu, EXCCODE_INE, 0); + + return RESUME_GUEST; +} + /* * LoongArch KVM callback handling for unimplemented guest exiting */ @@ -867,6 +875,7 @@ static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = { [EXCCODE_LASXDIS] = kvm_handle_lasx_disabled, [EXCCODE_GSPR] = kvm_handle_gspr, [EXCCODE_HVC] = kvm_handle_hypercall, + [EXCCODE_BTDIS] = kvm_handle_lbt_disabled, }; int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault) diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index 16756ffb55e8..36db2b257a95 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -977,12 +978,71 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu) return 0; } +#ifdef CONFIG_CPU_HAS_LBT +int kvm_own_lbt(struct kvm_vcpu *vcpu) +{ + if (!kvm_guest_has_lbt(&vcpu->arch)) + return -EINVAL; + + preempt_disable(); + set_csr_euen(CSR_EUEN_LBTEN); + + _restore_lbt(&vcpu->arch.lbt); + vcpu->arch.aux_inuse |= KVM_LARCH_LBT; + preempt_enable(); + return 0; +} + +static void kvm_lose_lbt(struct kvm_vcpu *vcpu) +{ + preempt_disable(); + if (vcpu->arch.aux_inuse & KVM_LARCH_LBT) { + _save_lbt(&vcpu->arch.lbt); + clear_csr_euen(CSR_EUEN_LBTEN); + vcpu->arch.aux_inuse &= ~KVM_LARCH_LBT; + } + preempt_enable(); +} + +static void kvm_check_fscr(struct kvm_vcpu *vcpu, unsigned long fcsr) +{ + /* + * If TM is enabled, top register save/restore will + * cause lbt exception, here enable lbt in advance + */ + if (fcsr & FPU_CSR_TM) + kvm_own_lbt(vcpu); +} + +static void kvm_check_fcsr_alive(struct kvm_vcpu *vcpu) +{ + unsigned long fcsr; + + if (vcpu->arch.aux_inuse & KVM_LARCH_FPU) { + if (vcpu->arch.aux_inuse & KVM_LARCH_LBT) + return; + + fcsr = read_fcsr(LOONGARCH_FCSR0); + kvm_check_fscr(vcpu, fcsr); + } +} +#else +static inline void kvm_lose_lbt(struct kvm_vcpu *vcpu) { } +static inline void kvm_check_fscr(struct kvm_vcpu *vcpu, + unsigned long fcsr) { } +static inline void kvm_check_fcsr_alive(struct kvm_vcpu *vcpu) { } +#endif + /* Enable FPU and restore context */ void kvm_own_fpu(struct kvm_vcpu *vcpu) { preempt_disable(); - /* Enable FPU */ + /* + * Enable FPU for guest + * Set FR and FRE according to guest context + */ + kvm_check_fscr(vcpu, vcpu->arch.fpu.fcsr); set_csr_euen(CSR_EUEN_FPEN); kvm_restore_fpu(&vcpu->arch.fpu); @@ -1002,6 +1062,7 @@ int kvm_own_lsx(struct kvm_vcpu *vcpu) preempt_disable(); /* Enable LSX for guest */ + kvm_check_fscr(vcpu, vcpu->arch.fpu.fcsr); set_csr_euen(CSR_EUEN_LSXEN | CSR_EUEN_FPEN); switch (vcpu->arch.aux_inuse & KVM_LARCH_FPU) { case KVM_LARCH_FPU: @@ -1036,6 +1097,7 @@ int kvm_own_lasx(struct kvm_vcpu *vcpu) preempt_disable(); + kvm_check_fscr(vcpu, vcpu->arch.fpu.fcsr); set_csr_euen(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN); switch (vcpu->arch.aux_inuse & (KVM_LARCH_FPU | KVM_LARCH_LSX)) { case KVM_LARCH_LSX: @@ -1067,6 +1129,7 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu) { preempt_disable(); + kvm_check_fcsr_alive(vcpu); if (vcpu->arch.aux_inuse & KVM_LARCH_LASX) { kvm_save_lasx(&vcpu->arch.fpu); vcpu->arch.aux_inuse &= ~(KVM_LARCH_LSX | KVM_LARCH_FPU | KVM_LARCH_LASX); @@ -1089,6 +1152,7 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu) /* Disable FPU */ clear_csr_euen(CSR_EUEN_FPEN); } + kvm_lose_lbt(vcpu); preempt_enable(); }