From: Anup Patel <Anup.Patel@wdc.com> To: Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, Albert Ou <aou@eecs.berkeley.edu>, Paolo Bonzini <pbonzini@redhat.com>, Radim K <rkrcmar@redhat.com> Cc: Alexander Graf <graf@amazon.com>, Atish Patra <Atish.Patra@wdc.com>, Alistair Francis <Alistair.Francis@wdc.com>, Damien Le Moal <Damien.LeMoal@wdc.com>, Christoph Hellwig <hch@lst.de>, Anup Patel <anup@brainfault.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, "kvm-riscv@lists.infradead.org" <kvm-riscv@lists.infradead.org>, "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Anup Patel <Anup.Patel@wdc.com> Subject: [PATCH v10 10/19] RISC-V: KVM: Handle WFI exits for VCPU Date: Mon, 23 Dec 2019 11:36:38 +0000 [thread overview] Message-ID: <20191223113443.68969-11-anup.patel@wdc.com> (raw) In-Reply-To: <20191223113443.68969-1-anup.patel@wdc.com> We get illegal instruction trap whenever Guest/VM executes WFI instruction. This patch handles WFI trap by blocking the trapped VCPU using kvm_vcpu_block() API. The blocked VCPU will be automatically resumed whenever a VCPU interrupt is injected from user-space or from in-kernel IRQCHIP emulation. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/riscv/kvm/vcpu_exit.c | 72 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c index cbf973c5f2fb..8d0ae1a23b70 100644 --- a/arch/riscv/kvm/vcpu_exit.c +++ b/arch/riscv/kvm/vcpu_exit.c @@ -12,6 +12,13 @@ #include <linux/kvm_host.h> #include <asm/csr.h> +#define INSN_OPCODE_MASK 0x007c +#define INSN_OPCODE_SHIFT 2 +#define INSN_OPCODE_SYSTEM 28 + +#define INSN_MASK_WFI 0xffffff00 +#define INSN_MATCH_WFI 0x10500000 + #define INSN_MATCH_LB 0x3 #define INSN_MASK_LB 0x707f #define INSN_MATCH_LH 0x1003 @@ -116,6 +123,67 @@ (s32)(((insn) >> 7) & 0x1f)) #define MASK_FUNCT3 0x7000 +static int truly_illegal_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + /* Redirect trap to Guest VCPU */ + kvm_riscv_vcpu_trap_redirect(vcpu, EXC_INST_ILLEGAL, insn); + + return 1; +} + +static int system_opcode_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + if ((insn & INSN_MASK_WFI) == INSN_MATCH_WFI) { + vcpu->stat.wfi_exit_stat++; + if (!kvm_arch_vcpu_runnable(vcpu)) { + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx); + kvm_vcpu_block(vcpu); + vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + kvm_clear_request(KVM_REQ_UNHALT, vcpu); + } + vcpu->arch.guest_context.sepc += INSN_LEN(insn); + return 1; + } + + return truly_illegal_insn(vcpu, run, insn); +} + +static int illegal_inst_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long insn) +{ + unsigned long ut_scause = 0; + struct kvm_cpu_context *ct; + + if (unlikely(INSN_IS_16BIT(insn))) { + if (insn == 0) { + ct = &vcpu->arch.guest_context; + insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, + ct->sepc, + &ut_scause); + if (ut_scause) { + if (ut_scause == EXC_LOAD_PAGE_FAULT) + ut_scause = EXC_INST_PAGE_FAULT; + kvm_riscv_vcpu_trap_redirect(vcpu, ut_scause, + ct->sepc); + return 1; + } + } + if (INSN_IS_16BIT(insn)) + return truly_illegal_insn(vcpu, run, insn); + } + + switch ((insn & INSN_OPCODE_MASK) >> INSN_OPCODE_SHIFT) { + case INSN_OPCODE_SYSTEM: + return system_opcode_insn(vcpu, run, insn); + default: + return truly_illegal_insn(vcpu, run, insn); + } +} + static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run, unsigned long fault_addr, unsigned long htinst) { @@ -537,6 +605,10 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, ret = -EFAULT; run->exit_reason = KVM_EXIT_UNKNOWN; switch (scause) { + case EXC_INST_ILLEGAL: + if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) + ret = illegal_inst_fault(vcpu, run, stval); + break; case EXC_INST_GUEST_PAGE_FAULT: case EXC_LOAD_GUEST_PAGE_FAULT: case EXC_STORE_GUEST_PAGE_FAULT: -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Anup Patel <Anup.Patel@wdc.com> To: Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, Albert Ou <aou@eecs.berkeley.edu>, Paolo Bonzini <pbonzini@redhat.com>, Radim K <rkrcmar@redhat.com> Cc: Damien Le Moal <Damien.LeMoal@wdc.com>, "kvm@vger.kernel.org" <kvm@vger.kernel.org>, Anup Patel <anup@brainfault.org>, Anup Patel <Anup.Patel@wdc.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Atish Patra <Atish.Patra@wdc.com>, Alistair Francis <Alistair.Francis@wdc.com>, "kvm-riscv@lists.infradead.org" <kvm-riscv@lists.infradead.org>, Alexander Graf <graf@amazon.com>, "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>, Christoph Hellwig <hch@lst.de> Subject: [PATCH v10 10/19] RISC-V: KVM: Handle WFI exits for VCPU Date: Mon, 23 Dec 2019 11:36:38 +0000 [thread overview] Message-ID: <20191223113443.68969-11-anup.patel@wdc.com> (raw) In-Reply-To: <20191223113443.68969-1-anup.patel@wdc.com> We get illegal instruction trap whenever Guest/VM executes WFI instruction. This patch handles WFI trap by blocking the trapped VCPU using kvm_vcpu_block() API. The blocked VCPU will be automatically resumed whenever a VCPU interrupt is injected from user-space or from in-kernel IRQCHIP emulation. Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/riscv/kvm/vcpu_exit.c | 72 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c index cbf973c5f2fb..8d0ae1a23b70 100644 --- a/arch/riscv/kvm/vcpu_exit.c +++ b/arch/riscv/kvm/vcpu_exit.c @@ -12,6 +12,13 @@ #include <linux/kvm_host.h> #include <asm/csr.h> +#define INSN_OPCODE_MASK 0x007c +#define INSN_OPCODE_SHIFT 2 +#define INSN_OPCODE_SYSTEM 28 + +#define INSN_MASK_WFI 0xffffff00 +#define INSN_MATCH_WFI 0x10500000 + #define INSN_MATCH_LB 0x3 #define INSN_MASK_LB 0x707f #define INSN_MATCH_LH 0x1003 @@ -116,6 +123,67 @@ (s32)(((insn) >> 7) & 0x1f)) #define MASK_FUNCT3 0x7000 +static int truly_illegal_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + /* Redirect trap to Guest VCPU */ + kvm_riscv_vcpu_trap_redirect(vcpu, EXC_INST_ILLEGAL, insn); + + return 1; +} + +static int system_opcode_insn(struct kvm_vcpu *vcpu, + struct kvm_run *run, + ulong insn) +{ + if ((insn & INSN_MASK_WFI) == INSN_MATCH_WFI) { + vcpu->stat.wfi_exit_stat++; + if (!kvm_arch_vcpu_runnable(vcpu)) { + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->arch.srcu_idx); + kvm_vcpu_block(vcpu); + vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + kvm_clear_request(KVM_REQ_UNHALT, vcpu); + } + vcpu->arch.guest_context.sepc += INSN_LEN(insn); + return 1; + } + + return truly_illegal_insn(vcpu, run, insn); +} + +static int illegal_inst_fault(struct kvm_vcpu *vcpu, struct kvm_run *run, + unsigned long insn) +{ + unsigned long ut_scause = 0; + struct kvm_cpu_context *ct; + + if (unlikely(INSN_IS_16BIT(insn))) { + if (insn == 0) { + ct = &vcpu->arch.guest_context; + insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, + ct->sepc, + &ut_scause); + if (ut_scause) { + if (ut_scause == EXC_LOAD_PAGE_FAULT) + ut_scause = EXC_INST_PAGE_FAULT; + kvm_riscv_vcpu_trap_redirect(vcpu, ut_scause, + ct->sepc); + return 1; + } + } + if (INSN_IS_16BIT(insn)) + return truly_illegal_insn(vcpu, run, insn); + } + + switch ((insn & INSN_OPCODE_MASK) >> INSN_OPCODE_SHIFT) { + case INSN_OPCODE_SYSTEM: + return system_opcode_insn(vcpu, run, insn); + default: + return truly_illegal_insn(vcpu, run, insn); + } +} + static int emulate_load(struct kvm_vcpu *vcpu, struct kvm_run *run, unsigned long fault_addr, unsigned long htinst) { @@ -537,6 +605,10 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, ret = -EFAULT; run->exit_reason = KVM_EXIT_UNKNOWN; switch (scause) { + case EXC_INST_ILLEGAL: + if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) + ret = illegal_inst_fault(vcpu, run, stval); + break; case EXC_INST_GUEST_PAGE_FAULT: case EXC_LOAD_GUEST_PAGE_FAULT: case EXC_STORE_GUEST_PAGE_FAULT: -- 2.17.1
next prev parent reply other threads:[~2019-12-23 11:36 UTC|newest] Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-12-23 11:35 [PATCH v10 00/19] KVM RISC-V Support Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:35 ` [PATCH v10 01/19] RISC-V: Export riscv_cpuid_to_hartid_mask() API Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:35 ` [PATCH v10 02/19] RISC-V: Add bitmap reprensenting ISA features common across CPUs Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:35 ` [PATCH v10 03/19] RISC-V: Add hypervisor extension related CSR defines Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:35 ` [PATCH v10 04/19] RISC-V: Add initial skeletal KVM support Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:35 ` [PATCH v10 05/19] RISC-V: KVM: Implement VCPU create, init and destroy functions Anup Patel 2019-12-23 11:35 ` Anup Patel 2019-12-23 11:36 ` [PATCH v10 06/19] RISC-V: KVM: Implement VCPU interrupts and requests handling Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:36 ` [PATCH v10 07/19] RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:36 ` [PATCH v10 08/19] RISC-V: KVM: Implement VCPU world-switch Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:36 ` [PATCH v10 09/19] RISC-V: KVM: Handle MMIO exits for VCPU Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:36 ` Anup Patel [this message] 2019-12-23 11:36 ` [PATCH v10 10/19] RISC-V: KVM: Handle WFI " Anup Patel 2019-12-23 11:36 ` [PATCH v10 11/19] RISC-V: KVM: Implement VMID allocator Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:36 ` [PATCH v10 12/19] RISC-V: KVM: Implement stage2 page table programming Anup Patel 2019-12-23 11:36 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 13/19] RISC-V: KVM: Implement MMU notifiers Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 14/19] RISC-V: KVM: Add timer functionality Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 15/19] RISC-V: KVM: FP lazy save/restore Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 16/19] RISC-V: KVM: Implement ONE REG interface for FP registers Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 17/19] RISC-V: KVM: Add SBI v0.1 support Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 18/19] RISC-V: KVM: Document RISC-V specific parts of KVM API Anup Patel 2019-12-23 11:37 ` Anup Patel 2019-12-23 11:37 ` [PATCH v10 19/19] RISC-V: KVM: Add MAINTAINERS entry Anup Patel 2019-12-23 11:37 ` Anup Patel 2020-01-16 1:45 ` [PATCH v10 00/19] KVM RISC-V Support Palmer Dabbelt 2020-01-16 1:45 ` Palmer Dabbelt 2020-01-16 16:51 ` [PATCH v10 01/19] RISC-V: Export riscv_cpuid_to_hartid_mask() API Palmer Dabbelt 2020-01-16 16:51 ` Palmer Dabbelt 2020-01-16 19:51 ` [PATCH v10 02/19] RISC-V: Add bitmap reprensenting ISA features common across CPUs Palmer Dabbelt 2020-01-16 19:51 ` Palmer Dabbelt 2020-01-17 6:45 ` Anup Patel 2020-01-17 6:45 ` Anup Patel 2020-01-16 19:51 ` [PATCH v10 03/19] RISC-V: Add hypervisor extension related CSR defines Palmer Dabbelt 2020-01-16 19:51 ` Palmer Dabbelt 2020-01-17 7:14 ` Anup Patel 2020-01-17 7:14 ` Anup Patel 2020-01-16 23:37 ` [PATCH v10 04/19] RISC-V: Add initial skeletal KVM support Palmer Dabbelt 2020-01-16 23:37 ` Palmer Dabbelt 2020-01-17 7:11 ` Anup Patel 2020-01-17 7:11 ` Anup Patel 2020-01-22 19:04 ` [PATCH v10 05/19] RISC-V: KVM: Implement VCPU create, init and destroy functions Palmer Dabbelt 2020-01-22 19:04 ` Palmer Dabbelt 2020-01-23 3:34 ` Anup Patel 2020-01-23 3:34 ` Anup Patel
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