| Message ID | 20210421134922.3309033-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: build perf support only when enabled | expand |
On Wed, 21 Apr 2021 14:49:01 +0100, Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > The perf_num_counters() function is only defined when CONFIG_PERF_EVENTS > is enabled: > > arch/arm64/kvm/perf.c: In function 'kvm_perf_init': > arch/arm64/kvm/perf.c:58:43: error: implicit declaration of function 'perf_num_counters'; did you mean 'dec_mm_counter'? [-Werror=implicit-function-declaration] > 58 | if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0 > | ^~~~~~~~~~~~~~~~~ > > Use conditional compilation to disable this feature entirely when > CONFIG_PERF_EVENTS is disabled in the host. > > Fixes: 6b5b368fccd7 ("KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > Not sure if this is the correct symbol to check for, but this is > one way to avoid the build failure. I think a better way is to get rid of perf_num_counters() entirely, see [1]. If someone acks the second and last patches, I'll even take the whole series in (nudge nudge...). Thanks, M. [1] https://lore.kernel.org/r/20210414134409.1266357-1-maz@kernel.org
On Wed, Apr 21, 2021 at 3:56 PM Marc Zyngier <maz@kernel.org> wrote: > On Wed, 21 Apr 2021 14:49:01 +0100, Arnd Bergmann <arnd@kernel.org> wrote: > > I think a better way is to get rid of perf_num_counters() entirely, > see [1]. If someone acks the second and last patches, I'll even take > the whole series in (nudge nudge...). Makes sense. I like your diffstat, too. Arnd
On Wed, Apr 21, 2021 at 02:56:16PM +0100, Marc Zyngier wrote: > On Wed, 21 Apr 2021 14:49:01 +0100, > Arnd Bergmann <arnd@kernel.org> wrote: > > > > From: Arnd Bergmann <arnd@arndb.de> > > > > The perf_num_counters() function is only defined when CONFIG_PERF_EVENTS > > is enabled: > > > > arch/arm64/kvm/perf.c: In function 'kvm_perf_init': > > arch/arm64/kvm/perf.c:58:43: error: implicit declaration of function 'perf_num_counters'; did you mean 'dec_mm_counter'? [-Werror=implicit-function-declaration] > > 58 | if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0 > > | ^~~~~~~~~~~~~~~~~ > > > > Use conditional compilation to disable this feature entirely when > > CONFIG_PERF_EVENTS is disabled in the host. > > > > Fixes: 6b5b368fccd7 ("KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key") > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > --- > > Not sure if this is the correct symbol to check for, but this is > > one way to avoid the build failure. > > I think a better way is to get rid of perf_num_counters() entirely, > see [1]. If someone acks the second and last patches, I'll even take > the whole series in (nudge nudge...). Sorry, behind at the moment! Will get to it today. Will
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 589921392cb1..9adf12ba5047 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -12,7 +12,7 @@ obj-$(CONFIG_KVM) += hyp/ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ $(KVM)/vfio.o $(KVM)/irqchip.o \ - arm.o mmu.o mmio.o psci.o perf.o hypercalls.o pvtime.o \ + arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o \ @@ -24,4 +24,6 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \ vgic/vgic-its.o vgic/vgic-debug.o +kvm-$(CONFIG_PERF_EVENTS) += perf.o + kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 4808aca8c87c..720e075c70f9 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1694,7 +1694,8 @@ static int init_subsystems(void) if (err) goto out; - kvm_perf_init(); + if (IS_ENABLED(CONFIG_PERF_EVENTS)) + kvm_perf_init(); kvm_sys_reg_table_init(); out: @@ -1899,7 +1900,8 @@ static int init_hyp_mode(void) return 0; out_err: - teardown_hyp_mode(); + if (IS_ENABLED(CONFIG_PERF_EVENTS)) + teardown_hyp_mode(); kvm_err("error initializing Hyp mode: %d\n", err); return err; } @@ -2101,7 +2103,7 @@ int kvm_arch_init(void *opaque) out_hyp: hyp_cpu_pm_exit(); - if (!in_hyp_mode) + if (!IS_ENABLED(CONFIG_PERF_EVENTS) && in_hyp_mode) teardown_hyp_mode(); out_err: return err; diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 6fd3cda608e4..d84307a1ebd5 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -13,12 +13,19 @@ #define ARMV8_PMU_CYCLE_IDX (ARMV8_PMU_MAX_COUNTERS - 1) #define ARMV8_PMU_MAX_COUNTER_PAIRS ((ARMV8_PMU_MAX_COUNTERS + 1) >> 1) +#ifdef CONFIG_PERF_EVENTS DECLARE_STATIC_KEY_FALSE(kvm_arm_pmu_available); static __always_inline bool kvm_arm_support_pmu_v3(void) { return static_branch_likely(&kvm_arm_pmu_available); } +#else +static __always_inline bool kvm_arm_support_pmu_v3(void) +{ + return 0; +} +#endif #ifdef CONFIG_HW_PERF_EVENTS