From: Fangyu Yu When executing HLV* instructions at the HS mode, a guest page fault may occur when a g-stage page table migration between triggering the virtual instruction exception and executing the HLV* instruction. This may be a corner case, and one simpler way to handle this is to re-execute the instruction where the virtual instruction exception occurred, and the guest page fault will be automatically handled. Fixes: 9f7013265112 ("RISC-V: KVM: Handle MMIO exits for VCPU") Signed-off-by: Fangyu Yu --- arch/riscv/kvm/vcpu_insn.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c index 97dec18e6989..a8b93aa4d8ec 100644 --- a/arch/riscv/kvm/vcpu_insn.c +++ b/arch/riscv/kvm/vcpu_insn.c @@ -448,7 +448,12 @@ int kvm_riscv_vcpu_virtual_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, ct->sepc, &utrap); - if (utrap.scause) { + switch (utrap.scause) { + case 0: + break; + case EXC_LOAD_GUEST_PAGE_FAULT: + return KVM_INSN_CONTINUE_SAME_SEPC; + default: utrap.sepc = ct->sepc; kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); return 1; @@ -503,7 +508,12 @@ int kvm_riscv_vcpu_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run, */ insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, ct->sepc, &utrap); - if (utrap.scause) { + switch (utrap.scause) { + case 0: + break; + case EXC_LOAD_GUEST_PAGE_FAULT: + return KVM_INSN_CONTINUE_SAME_SEPC; + default: /* Redirect trap if we failed to read instruction */ utrap.sepc = ct->sepc; kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); @@ -629,7 +639,12 @@ int kvm_riscv_vcpu_mmio_store(struct kvm_vcpu *vcpu, struct kvm_run *run, */ insn = kvm_riscv_vcpu_unpriv_read(vcpu, true, ct->sepc, &utrap); - if (utrap.scause) { + switch (utrap.scause) { + case 0: + break; + case EXC_LOAD_GUEST_PAGE_FAULT: + return KVM_INSN_CONTINUE_SAME_SEPC; + default: /* Redirect trap if we failed to read instruction */ utrap.sepc = ct->sepc; kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); -- 2.49.0