From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 40F8B1DA53 for ; Mon, 11 Nov 2024 13:47:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731332827; cv=none; b=GIjdWVq7weCv8z/UWyNf0d7WX9NpdMvvPG+jeIJ0Nqj/kRvN4Rn+A9G/c7yhm8uiK1L+M7uxNT6PsxzTrlhh4fLQWZ0260d0zdiAYxH4quehciay5CrZ4R9pKPi3xmClGfuDFYsi20vrL9U0lf466gAddXyr8T0nqF714QxqLIk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731332827; c=relaxed/simple; bh=BzA4qIPEfQN/OBP2Fu7Yp1/3+W2VaxpBuQfamWH+0rE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YQLCSXbiv16J/lUqYH23sQGphVQgrWg013i0+95Xx7k74X+5ei8xgELtUdIlkAZZQa9wu1E+7tnP0oe7RziKmH2QhOnfGbd+M2BlFGDY3Afb3cKmNpDnFfsulDbEbggLA4NtkM46GOlDHqG2ybOGZdnoWahzPcUk02U+HBMjDVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 066111CE0; Mon, 11 Nov 2024 05:47:34 -0800 (PST) Received: from [10.57.79.116] (unknown [10.57.79.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 561EB3F66E; Mon, 11 Nov 2024 05:47:02 -0800 (PST) Message-ID: Date: Mon, 11 Nov 2024 13:47:01 +0000 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 03/15] KVM: arm64: Track presence of SPE/TRBE in kvm_host_data instead of vCPU Content-Language: en-GB To: Oliver Upton , kvmarm@lists.linux.dev Cc: Marc Zyngier , Joey Gouly , Zenghui Yu , Mingwei Zhang , Colton Lewis , Alexandru Elisei , James Clark , james.clark2@arm.com References: <20241108222418.1677420-1-oliver.upton@linux.dev> <20241108222418.1677420-4-oliver.upton@linux.dev> From: Suzuki K Poulose In-Reply-To: <20241108222418.1677420-4-oliver.upton@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: James Clark Hi Oliver On 08/11/2024 22:24, Oliver Upton wrote: > Add flags to kvm_host_data to track if SPE/TRBE is present + > programmable on a per-CPU basis. Set the flags up at init rather than > vcpu_load() as the programmability of these buffers is unlikely to > change. > Heads up, there is a similar change from James Clark here : https://lkml.kernel.org/r/20241101155412.1152709-6-james.clark2@arm.com This change as such looks good to me. Suzuki > Signed-off-by: Oliver Upton > --- > arch/arm64/include/asm/kvm_host.h | 18 ++++++++------- > arch/arm64/kvm/arm.c | 3 --- > arch/arm64/kvm/debug.c | 36 ++++++++---------------------- > arch/arm64/kvm/hyp/nvhe/debug-sr.c | 8 +++---- > 4 files changed, 23 insertions(+), 42 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index ad514434f3fe..07da4129f1d1 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -610,6 +610,10 @@ struct cpu_sve_state { > * field. > */ > struct kvm_host_data { > +#define KVM_HOST_DATA_FLAG_HAS_SPE 0 > +#define KVM_HOST_DATA_FLAG_HAS_TRBE 1 > + unsigned long flags; > + > struct kvm_cpu_context host_ctxt; > > /* > @@ -911,10 +915,6 @@ struct kvm_vcpu_arch { > #define EXCEPT_AA64_EL2_SERR __vcpu_except_flags(7) > /* Guest debug is live */ > #define DEBUG_DIRTY __vcpu_single_flag(iflags, BIT(4)) > -/* Save SPE context if active */ > -#define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5)) > -/* Save TRBE context if active */ > -#define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) > > /* SVE enabled for host EL0 */ > #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) > @@ -1310,6 +1310,12 @@ DECLARE_KVM_HYP_PER_CPU(struct kvm_host_data, kvm_host_data); > &this_cpu_ptr_hyp_sym(kvm_host_data)->f) > #endif > > +#define host_data_test_flag(flag) \ > + (test_bit(KVM_HOST_DATA_FLAG_##flag, host_data_ptr(flags))) > +#define host_data_set_flag(flag) \ > + (set_bit(KVM_HOST_DATA_FLAG_##flag, host_data_ptr(flags))) > + > + > /* Check whether the FP regs are owned by the guest */ > static inline bool guest_owns_fp_regs(void) > { > @@ -1370,10 +1376,6 @@ static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr) > return (!has_vhe() && attr->exclude_host); > } > > -/* Flags for host debug state */ > -void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu); > -void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu); > - > #ifdef CONFIG_KVM > void kvm_set_pmu_events(u64 set, struct perf_event_attr *attr); > void kvm_clr_pmu_events(u64 clr); > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index ab1bf9ccf385..3822774840e1 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -617,15 +617,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) > > vcpu_set_pauth_traps(vcpu); > > - kvm_arch_vcpu_load_debug_state_flags(vcpu); > - > if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus)) > vcpu_set_on_unsupported_cpu(vcpu); > } > > void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) > { > - kvm_arch_vcpu_put_debug_state_flags(vcpu); > kvm_arch_vcpu_put_fp(vcpu); > if (has_vhe()) > kvm_vcpu_put_vhe(vcpu); > diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c > index 90ecf1210bd0..97d0c6fd5f61 100644 > --- a/arch/arm64/kvm/debug.c > +++ b/arch/arm64/kvm/debug.c > @@ -294,40 +294,22 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) > } > } > > -void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu) > +void kvm_init_host_debug_data(void) > { > - u64 dfr0; > + u64 dfr0 = read_sysreg(id_aa64dfr0_el1); > + > + if (cpuid_feature_extract_signed_field(dfr0, ID_AA64DFR0_EL1_PMUVer_SHIFT) > 0) > + *host_data_ptr(nr_event_counters) = FIELD_GET(ARMV8_PMU_PMCR_N, > + read_sysreg(pmcr_el0)); > > - /* For VHE, there is nothing to do */ > if (has_vhe()) > return; > > - dfr0 = read_sysreg(id_aa64dfr0_el1); > - /* > - * If SPE is present on this CPU and is available at current EL, > - * we may need to check if the host state needs to be saved. > - */ > if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_EL1_PMSVer_SHIFT) && > - !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(PMBIDR_EL1_P_SHIFT))) > - vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_SPE); > + !(read_sysreg_s(SYS_PMBIDR_EL1) & PMBIDR_EL1_P)) > + host_data_set_flag(HAS_SPE); > > - /* Check if we have TRBE implemented and available at the host */ > if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_EL1_TraceBuffer_SHIFT) && > !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_EL1_P)) > - vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_TRBE); > -} > - > -void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu) > -{ > - vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_SPE); > - vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRBE); > -} > - > -void kvm_init_host_debug_data(void) > -{ > - u64 dfr0 = read_sysreg(id_aa64dfr0_el1); > - > - if (cpuid_feature_extract_signed_field(dfr0, ID_AA64DFR0_EL1_PMUVer_SHIFT) > 0) > - *host_data_ptr(nr_event_counters) = FIELD_GET(ARMV8_PMU_PMCR_N, > - read_sysreg(pmcr_el0)); > + host_data_set_flag(HAS_TRBE); > } > diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c > index 1e2a26d0196e..858bb38e273f 100644 > --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c > +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c > @@ -82,10 +82,10 @@ static void __debug_restore_trace(u64 trfcr_el1) > void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) > { > /* Disable and flush SPE data generation */ > - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) > + if (host_data_test_flag(HAS_SPE)) > __debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1)); > /* Disable and flush Self-Hosted Trace generation */ > - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) > + if (host_data_test_flag(HAS_TRBE)) > __debug_save_trace(host_data_ptr(host_debug_state.trfcr_el1)); > } > > @@ -96,9 +96,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu) > > void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) > { > - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) > + if (host_data_test_flag(HAS_SPE)) > __debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1)); > - if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE)) > + if (host_data_test_flag(HAS_TRBE)) > __debug_restore_trace(*host_data_ptr(host_debug_state.trfcr_el1)); > } >