From a33c72faf2d73a35d85c8da4b65402a50aa7647c Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Mon, 27 Sep 2021 17:10:02 +0530 Subject: [PATCH] RISC-V: KVM: Implement VCPU create, init and destroy functions This patch implements VCPU create, init and destroy functions required by generic KVM module. We don't have much dynamic resources in struct kvm_vcpu_arch so these functions are quite simple for KVM RISC-V. Signed-off-by: Anup Patel Acked-by: Paolo Bonzini Reviewed-by: Paolo Bonzini Reviewed-by: Alexander Graf Acked-by: Palmer Dabbelt --- arch/riscv/include/asm/kvm_host.h | 69 +++++++++++++++++++++++++++++++ arch/riscv/kvm/vcpu.c | 55 ++++++++++++++++++++---- 2 files changed, 115 insertions(+), 9 deletions(-) diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index 08a8f53bf814..0db663cf74e4 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -57,7 +57,76 @@ struct kvm_cpu_trap { unsigned long htinst; }; +struct kvm_cpu_context { + unsigned long zero; + unsigned long ra; + unsigned long sp; + unsigned long gp; + unsigned long tp; + unsigned long t0; + unsigned long t1; + unsigned long t2; + unsigned long s0; + unsigned long s1; + unsigned long a0; + unsigned long a1; + unsigned long a2; + unsigned long a3; + unsigned long a4; + unsigned long a5; + unsigned long a6; + unsigned long a7; + unsigned long s2; + unsigned long s3; + unsigned long s4; + unsigned long s5; + unsigned long s6; + unsigned long s7; + unsigned long s8; + unsigned long s9; + unsigned long s10; + unsigned long s11; + unsigned long t3; + unsigned long t4; + unsigned long t5; + unsigned long t6; + unsigned long sepc; + unsigned long sstatus; + unsigned long hstatus; +}; + +struct kvm_vcpu_csr { + unsigned long vsstatus; + unsigned long vsie; + unsigned long vstvec; + unsigned long vsscratch; + unsigned long vsepc; + unsigned long vscause; + unsigned long vstval; + unsigned long hvip; + unsigned long vsatp; + unsigned long scounteren; +}; + struct kvm_vcpu_arch { + /* VCPU ran at least once */ + bool ran_atleast_once; + + /* ISA feature bits (similar to MISA) */ + unsigned long isa; + + /* CPU context of Guest VCPU */ + struct kvm_cpu_context guest_context; + + /* CPU CSR context of Guest VCPU */ + struct kvm_vcpu_csr guest_csr; + + /* CPU context upon Guest VCPU reset */ + struct kvm_cpu_context guest_reset_context; + + /* CPU CSR context upon Guest VCPU reset */ + struct kvm_vcpu_csr guest_reset_csr; + /* Don't run the VCPU (blocked) */ bool pause; diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 810b7ef30c0b..7b45aa23fba3 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -38,6 +38,27 @@ const struct kvm_stats_header kvm_vcpu_stats_header = { sizeof(kvm_vcpu_stats_desc), }; +#define KVM_RISCV_ISA_ALLOWED (riscv_isa_extension_mask(a) | \ + riscv_isa_extension_mask(c) | \ + riscv_isa_extension_mask(d) | \ + riscv_isa_extension_mask(f) | \ + riscv_isa_extension_mask(i) | \ + riscv_isa_extension_mask(m) | \ + riscv_isa_extension_mask(s) | \ + riscv_isa_extension_mask(u)) + +static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) +{ + struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr; + struct kvm_vcpu_csr *reset_csr = &vcpu->arch.guest_reset_csr; + struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; + struct kvm_cpu_context *reset_cntx = &vcpu->arch.guest_reset_context; + + memcpy(csr, reset_csr, sizeof(*csr)); + + memcpy(cntx, reset_cntx, sizeof(*cntx)); +} + int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) { return 0; @@ -45,7 +66,25 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id) int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) { - /* TODO: */ + struct kvm_cpu_context *cntx; + + /* Mark this VCPU never ran */ + vcpu->arch.ran_atleast_once = false; + + /* Setup ISA features available to VCPU */ + vcpu->arch.isa = riscv_isa_extension_base(NULL) & KVM_RISCV_ISA_ALLOWED; + + /* Setup reset state of shadow SSTATUS and HSTATUS CSRs */ + cntx = &vcpu->arch.guest_reset_context; + cntx->sstatus = SR_SPP | SR_SPIE; + cntx->hstatus = 0; + cntx->hstatus |= HSTATUS_VTW; + cntx->hstatus |= HSTATUS_SPVP; + cntx->hstatus |= HSTATUS_SPV; + + /* Reset VCPU */ + kvm_riscv_reset_vcpu(vcpu); + return 0; } @@ -53,15 +92,10 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) { } -int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) -{ - /* TODO: */ - return 0; -} - void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { - /* TODO: */ + /* Flush the pages pre-allocated for Stage2 page table mappings */ + kvm_riscv_stage2_flush_cache(vcpu); } int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) @@ -197,6 +231,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) struct kvm_cpu_trap trap; struct kvm_run *run = vcpu->run; + /* Mark this VCPU ran at least once */ + vcpu->arch.ran_atleast_once = true; + vcpu->arch.srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); /* Process MMIO value returned from user-space */ @@ -270,7 +307,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) * get an interrupt between __kvm_riscv_switch_to() and * local_irq_enable() which can potentially change CSRs. */ - trap.sepc = 0; + trap.sepc = vcpu->arch.guest_context.sepc; trap.scause = csr_read(CSR_SCAUSE); trap.stval = csr_read(CSR_STVAL); trap.htval = csr_read(CSR_HTVAL);