From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: [PATCH 05/14] arm/arm64: KVM: Statically configure the host's view of MPIDR Date: Thu, 24 Jan 2019 15:00:23 +0100 Message-ID: <20190124140032.8588-6-christoffer.dall@arm.com> References: <20190124140032.8588-1-christoffer.dall@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Marc Zyngier , kvm@vger.kernel.org To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Return-path: In-Reply-To: <20190124140032.8588-1-christoffer.dall@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org From: Marc Zyngier We currently eagerly save/restore MPIDR. It turns out to be slightly pointless: - On the host, this value is known as soon as we're scheduled on a physical CPU - In the guest, this value cannot change, as it is set by KVM (and this is a read-only register) The result of the above is that we can perfectly avoid the eager saving of MPIDR_EL1, and only keep the restore. We just have to setup the host contexts appropriately at boot time. Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 8 ++++++++ arch/arm/kvm/hyp/cp15-sr.c | 1 - arch/arm64/include/asm/kvm_host.h | 8 ++++++++ arch/arm64/kvm/hyp/sysreg-sr.c | 1 - virt/kvm/arm/arm.c | 1 + 5 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 4b6193f2f0f6..43e343e00fb8 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -26,6 +26,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -147,6 +148,13 @@ struct kvm_cpu_context { typedef struct kvm_cpu_context kvm_cpu_context_t; +static inline void kvm_init_host_cpu_context(kvm_cpu_context_t *cpu_ctxt, + int cpu) +{ + /* The host's MPIDR is immutable, so let's set it up at boot time */ + cpu_ctxt->cp15[c0_MPIDR] = cpu_logical_map(cpu); +} + struct kvm_vcpu_arch { struct kvm_cpu_context ctxt; diff --git a/arch/arm/kvm/hyp/cp15-sr.c b/arch/arm/kvm/hyp/cp15-sr.c index c4782812714c..8bf895ec6e04 100644 --- a/arch/arm/kvm/hyp/cp15-sr.c +++ b/arch/arm/kvm/hyp/cp15-sr.c @@ -27,7 +27,6 @@ static u64 *cp15_64(struct kvm_cpu_context *ctxt, int idx) void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) { - ctxt->cp15[c0_MPIDR] = read_sysreg(VMPIDR); ctxt->cp15[c0_CSSELR] = read_sysreg(CSSELR); ctxt->cp15[c1_SCTLR] = read_sysreg(SCTLR); ctxt->cp15[c1_CPACR] = read_sysreg(CPACR); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8b7702bdb219..f497bb31031f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -30,6 +30,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -418,6 +419,13 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); DECLARE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state); +static inline void kvm_init_host_cpu_context(kvm_cpu_context_t *cpu_ctxt, + int cpu) +{ + /* The host's MPIDR is immutable, so let's set it up at boot time */ + cpu_ctxt->sys_regs[MPIDR_EL1] = cpu_logical_map(cpu); +} + void __kvm_enable_ssbs(void); static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 68d6f7c3b237..2498f86defcb 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -52,7 +52,6 @@ static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt) static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { - ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2); ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1); ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr); ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 4d55f98f97f7..3dd240ea9e76 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1561,6 +1561,7 @@ static int init_hyp_mode(void) kvm_cpu_context_t *cpu_ctxt; cpu_ctxt = per_cpu_ptr(&kvm_host_cpu_state, cpu); + kvm_init_host_cpu_context(cpu_ctxt, cpu); err = create_hyp_mappings(cpu_ctxt, cpu_ctxt + 1, PAGE_HYP); if (err) { -- 2.18.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 455F5C282C3 for ; 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Thu, 24 Jan 2019 06:00:47 -0800 (PST) From: Christoffer Dall To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: [PATCH 05/14] arm/arm64: KVM: Statically configure the host's view of MPIDR Date: Thu, 24 Jan 2019 15:00:23 +0100 Message-Id: <20190124140032.8588-6-christoffer.dall@arm.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190124140032.8588-1-christoffer.dall@arm.com> References: <20190124140032.8588-1-christoffer.dall@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190124_060052_788871_A456DD8B X-CRM114-Status: GOOD ( 14.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marc Zyngier , kvm@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Marc Zyngier We currently eagerly save/restore MPIDR. It turns out to be slightly pointless: - On the host, this value is known as soon as we're scheduled on a physical CPU - In the guest, this value cannot change, as it is set by KVM (and this is a read-only register) The result of the above is that we can perfectly avoid the eager saving of MPIDR_EL1, and only keep the restore. We just have to setup the host contexts appropriately at boot time. Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall --- arch/arm/include/asm/kvm_host.h | 8 ++++++++ arch/arm/kvm/hyp/cp15-sr.c | 1 - arch/arm64/include/asm/kvm_host.h | 8 ++++++++ arch/arm64/kvm/hyp/sysreg-sr.c | 1 - virt/kvm/arm/arm.c | 1 + 5 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 4b6193f2f0f6..43e343e00fb8 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -26,6 +26,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -147,6 +148,13 @@ struct kvm_cpu_context { typedef struct kvm_cpu_context kvm_cpu_context_t; +static inline void kvm_init_host_cpu_context(kvm_cpu_context_t *cpu_ctxt, + int cpu) +{ + /* The host's MPIDR is immutable, so let's set it up at boot time */ + cpu_ctxt->cp15[c0_MPIDR] = cpu_logical_map(cpu); +} + struct kvm_vcpu_arch { struct kvm_cpu_context ctxt; diff --git a/arch/arm/kvm/hyp/cp15-sr.c b/arch/arm/kvm/hyp/cp15-sr.c index c4782812714c..8bf895ec6e04 100644 --- a/arch/arm/kvm/hyp/cp15-sr.c +++ b/arch/arm/kvm/hyp/cp15-sr.c @@ -27,7 +27,6 @@ static u64 *cp15_64(struct kvm_cpu_context *ctxt, int idx) void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt) { - ctxt->cp15[c0_MPIDR] = read_sysreg(VMPIDR); ctxt->cp15[c0_CSSELR] = read_sysreg(CSSELR); ctxt->cp15[c1_SCTLR] = read_sysreg(SCTLR); ctxt->cp15[c1_CPACR] = read_sysreg(CPACR); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8b7702bdb219..f497bb31031f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -30,6 +30,7 @@ #include #include #include +#include #include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -418,6 +419,13 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); DECLARE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state); +static inline void kvm_init_host_cpu_context(kvm_cpu_context_t *cpu_ctxt, + int cpu) +{ + /* The host's MPIDR is immutable, so let's set it up at boot time */ + cpu_ctxt->sys_regs[MPIDR_EL1] = cpu_logical_map(cpu); +} + void __kvm_enable_ssbs(void); static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 68d6f7c3b237..2498f86defcb 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -52,7 +52,6 @@ static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt) static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { - ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2); ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1); ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr); ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 4d55f98f97f7..3dd240ea9e76 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1561,6 +1561,7 @@ static int init_hyp_mode(void) kvm_cpu_context_t *cpu_ctxt; cpu_ctxt = per_cpu_ptr(&kvm_host_cpu_state, cpu); + kvm_init_host_cpu_context(cpu_ctxt, cpu); err = create_hyp_mappings(cpu_ctxt, cpu_ctxt + 1, PAGE_HYP); if (err) { -- 2.18.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel