| Message ID | 20230127182558.2416400-10-atishp@rivosinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | KVM perf support | expand |
| Context | Check | Description |
|---|---|---|
| conchuod/cover_letter | success | Series has a cover letter |
| conchuod/tree_selection | success | Guessed tree name to be for-next |
| conchuod/fixes_present | success | Fixes tag not required for -next series |
| conchuod/maintainers_pattern | success | MAINTAINERS pattern errors before the patch: 13 and now 13 |
| conchuod/verify_signedoff | success | Signed-off-by tag matches author and committer |
| conchuod/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/module_param | success | Was 0 now: 0 |
| conchuod/build_rv64_gcc_allmodconfig | success | Errors and warnings before: 0 this patch: 0 |
| conchuod/alphanumeric_selects | success | Out of order selects before the patch: 57 and now 57 |
| conchuod/build_rv32_defconfig | success | Build OK |
| conchuod/dtb_warn_rv64 | success | Errors and warnings before: 2 this patch: 2 |
| conchuod/header_inline | success | No static functions without inline keyword in header files |
| conchuod/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 14 lines checked |
| conchuod/source_inline | success | Was 0 now: 0 |
| conchuod/build_rv64_nommu_k210_defconfig | success | Build OK |
| conchuod/verify_fixes | success | No Fixes tag |
| conchuod/build_rv64_nommu_virt_defconfig | success | Build OK |
On Fri, Jan 27, 2023 at 11:56 PM Atish Patra <atishp@rivosinc.com> wrote: > > The privilege mode filtering feature must be available in the host so > that the host can inhibit the counters while the execution is in HS mode. > Otherwise, the guests may have access to critical guest information. > > Signed-off-by: Atish Patra <atishp@rivosinc.com> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> Regards, Anup > --- > arch/riscv/kvm/vcpu_pmu.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c > index d3fd551..7713927 100644 > --- a/arch/riscv/kvm/vcpu_pmu.c > +++ b/arch/riscv/kvm/vcpu_pmu.c > @@ -79,6 +79,14 @@ int kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) > struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); > struct kvm_pmc *pmc; > > + /* > + * PMU functionality should be only available to guests if privilege mode > + * filtering is available in the host. Otherwise, guest will always count > + * events while the execution is in hypervisor mode. > + */ > + if (!riscv_isa_extension_available(NULL, SSCOFPMF)) > + return 0; > + > ret = riscv_pmu_get_hpm_info(&hpm_width, &num_hw_ctrs); > if (ret < 0) > return ret; > -- > 2.25.1 >
diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index d3fd551..7713927 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -79,6 +79,14 @@ int kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu) struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; + /* + * PMU functionality should be only available to guests if privilege mode + * filtering is available in the host. Otherwise, guest will always count + * events while the execution is in hypervisor mode. + */ + if (!riscv_isa_extension_available(NULL, SSCOFPMF)) + return 0; + ret = riscv_pmu_get_hpm_info(&hpm_width, &num_hw_ctrs); if (ret < 0) return ret;
The privilege mode filtering feature must be available in the host so that the host can inhibit the counters while the execution is in HS mode. Otherwise, the guests may have access to critical guest information. Signed-off-by: Atish Patra <atishp@rivosinc.com> --- arch/riscv/kvm/vcpu_pmu.c | 8 ++++++++ 1 file changed, 8 insertions(+)