From patchwork Fri Feb 22 16:25:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10826543 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6D8A013B5 for ; Fri, 22 Feb 2019 16:27:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5BCF1313C6 for ; Fri, 22 Feb 2019 16:27:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4F6C9315BD; Fri, 22 Feb 2019 16:27:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CF06E313C6 for ; Fri, 22 Feb 2019 16:27:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727157AbfBVQ11 (ORCPT ); Fri, 22 Feb 2019 11:27:27 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36004 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726647AbfBVQ10 (ORCPT ); Fri, 22 Feb 2019 11:27:26 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3736780D; Fri, 22 Feb 2019 08:27:26 -0800 (PST) Received: from big-swifty.lan (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0617C3F5C1; Fri, 22 Feb 2019 08:27:19 -0800 (PST) From: Marc Zyngier To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Cc: Andre Przywara , Ard Biesheuvel , Christoffer Dall , Colin Ian King , Daniel Lezcano , Dave Martin , James Morse , Julien Thierry , Masahiro Yamada , Shaokun Zhang , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 06/27] arm/arm64: KVM: Statically configure the host's view of MPIDR Date: Fri, 22 Feb 2019 16:25:44 +0000 Message-Id: <20190222162605.5054-7-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190222162605.5054-1-marc.zyngier@arm.com> References: <20190222162605.5054-1-marc.zyngier@arm.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Signed-off-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) {