diff options
| author | Anup Patel <apatel@ventanamicro.com> | 2022-07-29 17:14:53 +0530 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2022-07-29 17:14:53 +0530 |
| commit | 8a061562e2f2b32bfb5bff5bf3afc64e37d95a27 (patch) | |
| tree | ca9fef5fb33c95fe9580daf738f3c033e5c92270 /arch/riscv/kvm/vcpu.c | |
| parent | 1222b55cee2396a1a286e924d9f6abb6d7a04f55 (diff) | |
| download | lwn-8a061562e2f2b32bfb5bff5bf3afc64e37d95a27.tar.gz lwn-8a061562e2f2b32bfb5bff5bf3afc64e37d95a27.zip | |
RISC-V: KVM: Add extensible CSR emulation framework
We add an extensible CSR emulation framework which is based upon the
existing system instruction emulation. This will be useful to upcoming
AIA, PMU, Nested and other virtualization features.
The CSR emulation framework also has provision to emulate CSR in user
space but this will be used only in very specific cases such as AIA
IMSIC CSR emulation in user space or vendor specific CSR emulation
in user space.
By default, all CSRs not handled by KVM RISC-V will be redirected back
to Guest VCPU as illegal instruction trap.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Diffstat (limited to 'arch/riscv/kvm/vcpu.c')
| -rw-r--r-- | arch/riscv/kvm/vcpu.c | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index a3c051cb070c..3c95924d38c7 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -26,6 +26,8 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { STATS_DESC_COUNTER(VCPU, wfi_exit_stat), STATS_DESC_COUNTER(VCPU, mmio_exit_user), STATS_DESC_COUNTER(VCPU, mmio_exit_kernel), + STATS_DESC_COUNTER(VCPU, csr_exit_user), + STATS_DESC_COUNTER(VCPU, csr_exit_kernel), STATS_DESC_COUNTER(VCPU, exits) }; @@ -899,22 +901,26 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) kvm_vcpu_srcu_read_lock(vcpu); - /* Process MMIO value returned from user-space */ - if (run->exit_reason == KVM_EXIT_MMIO) { + switch (run->exit_reason) { + case KVM_EXIT_MMIO: + /* Process MMIO value returned from user-space */ ret = kvm_riscv_vcpu_mmio_return(vcpu, vcpu->run); - if (ret) { - kvm_vcpu_srcu_read_unlock(vcpu); - return ret; - } - } - - /* Process SBI value returned from user-space */ - if (run->exit_reason == KVM_EXIT_RISCV_SBI) { + break; + case KVM_EXIT_RISCV_SBI: + /* Process SBI value returned from user-space */ ret = kvm_riscv_vcpu_sbi_return(vcpu, vcpu->run); - if (ret) { - kvm_vcpu_srcu_read_unlock(vcpu); - return ret; - } + break; + case KVM_EXIT_RISCV_CSR: + /* Process CSR value returned from user-space */ + ret = kvm_riscv_vcpu_csr_return(vcpu, vcpu->run); + break; + default: + ret = 0; + break; + } + if (ret) { + kvm_vcpu_srcu_read_unlock(vcpu); + return ret; } if (run->immediate_exit) { |