diff options
Diffstat (limited to 'arch/riscv/kvm/vmid.c')
| -rw-r--r-- | arch/riscv/kvm/vmid.c | 33 |
1 files changed, 29 insertions, 4 deletions
diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c index 6cd93995fb65..3b426c800480 100644 --- a/arch/riscv/kvm/vmid.c +++ b/arch/riscv/kvm/vmid.c @@ -14,21 +14,23 @@ #include <linux/smp.h> #include <linux/kvm_host.h> #include <asm/csr.h> +#include <asm/kvm_tlb.h> +#include <asm/kvm_vmid.h> static unsigned long vmid_version = 1; static unsigned long vmid_next; -static unsigned long vmid_bits; +static unsigned long vmid_bits __ro_after_init; static DEFINE_SPINLOCK(vmid_lock); -void kvm_riscv_gstage_vmid_detect(void) +void __init kvm_riscv_gstage_vmid_detect(void) { unsigned long old; /* Figure-out number of VMID bits in HW */ old = csr_read(CSR_HGATP); - csr_write(CSR_HGATP, old | HGATP_VMID_MASK); + csr_write(CSR_HGATP, old | HGATP_VMID); vmid_bits = csr_read(CSR_HGATP); - vmid_bits = (vmid_bits & HGATP_VMID_MASK) >> HGATP_VMID_SHIFT; + vmid_bits = (vmid_bits & HGATP_VMID) >> HGATP_VMID_SHIFT; vmid_bits = fls_long(vmid_bits); csr_write(CSR_HGATP, old); @@ -122,3 +124,26 @@ void kvm_riscv_gstage_vmid_update(struct kvm_vcpu *vcpu) kvm_for_each_vcpu(i, v, vcpu->kvm) kvm_make_request(KVM_REQ_UPDATE_HGATP, v); } + +void kvm_riscv_gstage_vmid_sanitize(struct kvm_vcpu *vcpu) +{ + unsigned long vmid; + + if (!kvm_riscv_gstage_vmid_bits() || + vcpu->arch.last_exit_cpu == vcpu->cpu) + return; + + /* + * On RISC-V platforms with hardware VMID support, we share same + * VMID for all VCPUs of a particular Guest/VM. This means we might + * have stale G-stage TLB entries on the current Host CPU due to + * some other VCPU of the same Guest which ran previously on the + * current Host CPU. + * + * To cleanup stale TLB entries, we simply flush all G-stage TLB + * entries by VMID whenever underlying Host CPU changes for a VCPU. + */ + + vmid = READ_ONCE(vcpu->kvm->arch.vmid.vmid); + kvm_riscv_local_hfence_gvma_vmid_all(vmid); +} |