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=-9.1 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 574B2C43381 for ; Mon, 18 Feb 2019 19:59:30 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 04A9221773 for ; Mon, 18 Feb 2019 19:59:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jEHNs3B/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04A9221773 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=ha7qEp31OehN5VmYm52tb2d+0E4fdLh1c6AaIuJ0Z4M=; b=jEHNs3B/fDsJX4L8UsctQw9sAz QHgZ6P8IymFGZY9nZIDKZTV2DiH80lOJlD6UVaU26QPjnRhyyqpDTV+yBSzj0TlYWWOjrlNeaYcoC frT/yhBPmnU9yVHc/wrFMWkIYqALwrh6HhEU54PzIPIkm3Zk4ittTtjK0nJA4tGacV0zTmFMpleVI Og7ZZduDBspiTppwuk1EJ0l2xderFmDJxvlDCfPeYUiVQym+voqjl4GGDQySyMWVLniloXzZBa0tb u8S6obhpGjyZzlQ1m4TRA6QEK6qreJq+JWyhjF/icMKbTr729foSVs/U3wwXmu/yQSIxRihTRSWD+ aVAYlnsg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvp4T-0003FK-St; Mon, 18 Feb 2019 19:59:21 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gvozz-0004c0-Os for linux-arm-kernel@lists.infradead.org; Mon, 18 Feb 2019 19:55:15 +0000 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 19DE61CDD; Mon, 18 Feb 2019 11:54:19 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 015C63FB75; Mon, 18 Feb 2019 11:53:56 -0800 (PST) From: Dave Martin To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v5 14/26] KVM: arm64/sve: Context switch the SVE registers Date: Mon, 18 Feb 2019 19:52:27 +0000 Message-Id: <1550519559-15915-15-git-send-email-Dave.Martin@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> References: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190218_115444_236983_1FAC68D3 X-CRM114-Status: GOOD ( 19.70 ) 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: Peter Maydell , Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Zhang Lei , Julien Grall , =?UTF-8?q?Alex=20Benn=C3=A9e?= , linux-arm-kernel@lists.infradead.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 In order to give each vcpu its own view of the SVE registers, this patch adds context storage via a new sve_state pointer in struct vcpu_arch. An additional member sve_max_vl is also added for each vcpu, to determine the maximum vector length visible to the guest and thus the value to be configured in ZCR_EL2.LEN while the is active. This also determines the layout and size of the storage in sve_state, which is read and written by the same backend functions that are used for context-switching the SVE state for host tasks. On SVE-enabled vcpus, SVE access traps are now handled by switching in the vcpu's SVE context and disabling the trap before returning to the guest. On other vcpus, the trap is not handled and an exit back to the host occurs, where the handle_sve() fallback path reflects an undefined instruction exception back to the guest, consistently with the behaviour of non-SVE-capable hardware (as was done unconditionally prior to this patch). No SVE handling is added on non-VHE-only paths, since VHE is an architectural and Kconfig prerequisite of SVE. Signed-off-by: Dave Martin --- Changes since v4: * Remove if_sve() helper in favour of open-coded static key checks. * Explicitly merge static key checks and other condition checks to reduce overhead and maximise const-folding and specialisation opportunities in the compiler. --- arch/arm64/include/asm/kvm_host.h | 6 ++++ arch/arm64/kvm/fpsimd.c | 5 +-- arch/arm64/kvm/hyp/switch.c | 70 +++++++++++++++++++++++++++++---------- 3 files changed, 61 insertions(+), 20 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index c32f195..77b6f3e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -212,6 +212,8 @@ typedef struct kvm_cpu_context kvm_cpu_context_t; struct kvm_vcpu_arch { struct kvm_cpu_context ctxt; + void *sve_state; + unsigned int sve_max_vl; /* HYP configuration */ u64 hcr_el2; @@ -304,6 +306,10 @@ struct kvm_vcpu_arch { bool sysregs_loaded_on_cpu; }; +/* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */ +#define vcpu_sve_pffr(vcpu) ((void *)((char *)((vcpu)->arch.sve_state) + \ + sve_ffr_offset((vcpu)->arch.sve_max_vl))) + /* vcpu_arch flags field values: */ #define KVM_ARM64_DEBUG_DIRTY (1 << 0) #define KVM_ARM64_FP_ENABLED (1 << 1) /* guest FP regs loaded */ diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 7053bf4..6e3c9c8 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -87,10 +87,11 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { fpsimd_bind_state_to_cpu(&vcpu->arch.ctxt.gp_regs.fp_regs, - NULL, SVE_VL_MIN); + vcpu->arch.sve_state, + vcpu->arch.sve_max_vl); clear_thread_flag(TIF_FOREIGN_FPSTATE); - clear_thread_flag(TIF_SVE); + update_thread_flag(TIF_SVE, vcpu_has_sve(vcpu)); } } diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 9f07403..cdc9063 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -98,7 +98,10 @@ static void activate_traps_vhe(struct kvm_vcpu *vcpu) val = read_sysreg(cpacr_el1); val |= CPACR_EL1_TTA; val &= ~CPACR_EL1_ZEN; - if (!update_fp_enabled(vcpu)) { + if (update_fp_enabled(vcpu)) { + if (vcpu_has_sve(vcpu)) + val |= CPACR_EL1_ZEN; + } else { val &= ~CPACR_EL1_FPEN; __activate_traps_fpsimd32(vcpu); } @@ -313,16 +316,43 @@ static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu) return true; } -static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu) +/* Check for an FPSIMD/SVE trap and handle as appropriate */ +static bool __hyp_text __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) { - struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state; + bool vhe, sve_guest, sve_host; + u8 trap_class; - if (has_vhe()) - write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN, - cpacr_el1); - else + if (!system_supports_fpsimd()) + return false; + + if (system_supports_sve()) { + sve_guest = vcpu_has_sve(vcpu); + sve_host = vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE; + vhe = true; + } else { + sve_guest = false; + sve_host = false; + vhe = has_vhe(); + } + + trap_class = kvm_vcpu_trap_get_class(vcpu); + if (trap_class != ESR_ELx_EC_FP_ASIMD && + (!sve_guest || trap_class != ESR_ELx_EC_SVE)) + return false; + + /* The trap is an FPSIMD/SVE trap: switch the context */ + + if (vhe) { + u64 reg = read_sysreg(cpacr_el1) | CPACR_EL1_FPEN; + + if (sve_guest) + reg |= CPACR_EL1_ZEN; + + write_sysreg(reg, cpacr_el1); + } else { write_sysreg(read_sysreg(cptr_el2) & ~(u64)CPTR_EL2_TFP, cptr_el2); + } isb(); @@ -331,24 +361,28 @@ static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu) * In the SVE case, VHE is assumed: it is enforced by * Kconfig and kvm_arch_init(). */ - if (system_supports_sve() && - (vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE)) { + if (sve_host) { struct thread_struct *thread = container_of( - host_fpsimd, + vcpu->arch.host_fpsimd_state, struct thread_struct, uw.fpsimd_state); - sve_save_state(sve_pffr(thread), &host_fpsimd->fpsr); + sve_save_state(sve_pffr(thread), + &vcpu->arch.host_fpsimd_state->fpsr); } else { - __fpsimd_save_state(host_fpsimd); + __fpsimd_save_state(vcpu->arch.host_fpsimd_state); } vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; } - __fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs); - - if (vcpu_has_sve(vcpu)) + if (sve_guest) { + sve_load_state(vcpu_sve_pffr(vcpu), + &vcpu->arch.ctxt.gp_regs.fp_regs.fpsr, + sve_vq_from_vl(vcpu->arch.sve_max_vl) - 1); write_sysreg_s(vcpu->arch.ctxt.sys_regs[ZCR_EL1], SYS_ZCR_EL12); + } else { + __fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs); + } /* Skip restoring fpexc32 for AArch64 guests */ if (!(read_sysreg(hcr_el2) & HCR_RW)) @@ -384,10 +418,10 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code) * and restore the guest context lazily. * If FP/SIMD is not implemented, handle the trap and inject an * undefined instruction exception to the guest. + * Similarly for trapped SVE accesses. */ - if (system_supports_fpsimd() && - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_FP_ASIMD) - return __hyp_switch_fpsimd(vcpu); + if (__hyp_handle_fpsimd(vcpu)) + return true; if (!__populate_fault_info(vcpu)) return true; -- 2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel