From patchwork Fri May 31 23:13:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Upton X-Patchwork-Id: 13682267 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0594312F5B3 for ; Fri, 31 May 2024 23:14:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717197266; cv=none; b=SKjk6/vwvo1tZDYOiPdR3ajK66FfFptzGIa/7WHlfP87J4c3XDt+vnM7ti8kfjATrvOSO9bNLHucs4zy2OYdWzxY0ezM96eVS35lijTJtDpHytI40mHd6j1GsrPN8GkmS3PtE/KNpmXea1w1LgyEvCFFIMeNbDpsk6bTDjFpmgw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717197266; c=relaxed/simple; bh=GQLmpLEJpZCcxYIrQKwBbYXAdNIe7Oqcd/jiMpVJ4hQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Drg4bukzCnDIAy+L6mh1kzNS6DerOQKVlEAY4YegLlt/x91iTW8XJxQFuW7ws6y6k9EuQE3qFBKuMtpT9w03guOEt71G9BeFa+PVoGXw/bLdHlt+2NFXid2biiO04YN2ve1KBhcumS2hAR/clsIZP/CoZ+LEa3qIirhWTrvaTP8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=GsBamMFb; arc=none smtp.client-ip=91.218.175.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="GsBamMFb" X-Envelope-To: kvmarm@lists.linux.dev DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717197262; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6UxvKsGCyjIAUWY8dK13u5dkkNDiZQb2bow6ZF/6Aqk=; b=GsBamMFbbt0/DaM0h0j03fZ34YQfqQnUkIYf4Vj1+2rvfWVBvCqIKXbFWY9qF/M4gsAFOD KdDqsAugkSPxJN1lWDBIBfS3sRx8DizQXSIVWMXWuvQcf/aXucVat62mqycgMN2yAjDxpW 9RTFB5dq/6Nc9QOTpigGkJhpPmctkx0= X-Envelope-To: maz@kernel.org X-Envelope-To: james.morse@arm.com X-Envelope-To: suzuki.poulose@arm.com X-Envelope-To: yuzenghui@huawei.com X-Envelope-To: kvm@vger.kernel.org X-Envelope-To: oliver.upton@linux.dev X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , kvm@vger.kernel.org, Oliver Upton Subject: [PATCH 05/11] KVM: arm64: nv: Handle ZCR_EL2 traps Date: Fri, 31 May 2024 23:13:52 +0000 Message-ID: <20240531231358.1000039-6-oliver.upton@linux.dev> In-Reply-To: <20240531231358.1000039-1-oliver.upton@linux.dev> References: <20240531231358.1000039-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Unlike other SVE-related registers, ZCR_EL2 takes a sysreg trap to EL2 when HCR_EL2.NV = 1. KVM still needs to honor the guest hypervisor's trap configuration, which expects an SVE trap (i.e. ESR_EL2.EC = 0x19) when CPTR traps are enabled for the vCPU's current context. Otherwise, if the guest hypervisor has traps disabled, emulate the access by mapping the requested VL into ZCR_EL1. Signed-off-by: Oliver Upton --- Notes, because I'm too lazy to respin before sending on a Friday: - I'll want to add a helper for synthesizing the SVE trap, open-coding it in the sysreg handler is gross. - The sysreg handler needs to check CPACR_ELx_FPEN in addition to _ZEN, like what I have now. arch/arm64/include/asm/kvm_host.h | 3 +++ arch/arm64/kvm/sys_regs.c | 40 +++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e01e6de414f1..aeb1c567dfad 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -422,6 +422,7 @@ enum vcpu_sysreg { MDCR_EL2, /* Monitor Debug Configuration Register (EL2) */ CPTR_EL2, /* Architectural Feature Trap Register (EL2) */ HACR_EL2, /* Hypervisor Auxiliary Control Register */ + ZCR_EL2, /* SVE Control Register (EL2) */ TTBR0_EL2, /* Translation Table Base Register 0 (EL2) */ TTBR1_EL2, /* Translation Table Base Register 1 (EL2) */ TCR_EL2, /* Translation Control Register (EL2) */ @@ -972,6 +973,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) case DACR32_EL2: *val = read_sysreg_s(SYS_DACR32_EL2); break; case IFSR32_EL2: *val = read_sysreg_s(SYS_IFSR32_EL2); break; case DBGVCR32_EL2: *val = read_sysreg_s(SYS_DBGVCR32_EL2); break; + case ZCR_EL1: *val = read_sysreg_s(SYS_ZCR_EL12); break; default: return false; } @@ -1017,6 +1019,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) case DACR32_EL2: write_sysreg_s(val, SYS_DACR32_EL2); break; case IFSR32_EL2: write_sysreg_s(val, SYS_IFSR32_EL2); break; case DBGVCR32_EL2: write_sysreg_s(val, SYS_DBGVCR32_EL2); break; + case ZCR_EL1: write_sysreg_s(val, SYS_ZCR_EL12); break; default: return false; } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 22b45a15d068..a662e9d2d917 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -121,6 +121,7 @@ static bool get_el2_to_el1_mapping(unsigned int reg, MAPPED_EL2_SYSREG(AMAIR_EL2, AMAIR_EL1, NULL ); MAPPED_EL2_SYSREG(ELR_EL2, ELR_EL1, NULL ); MAPPED_EL2_SYSREG(SPSR_EL2, SPSR_EL1, NULL ); + MAPPED_EL2_SYSREG(ZCR_EL2, ZCR_EL1, NULL ); default: return false; } @@ -2199,6 +2200,42 @@ static u64 reset_hcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) return __vcpu_sys_reg(vcpu, r->reg) = val; } +static unsigned int sve_el2_visibility(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *rd) +{ + unsigned int r; + + r = el2_visibility(vcpu, rd); + if (r) + return r; + + return sve_visibility(vcpu, rd); +} + +static bool access_zcr_el2(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 esr = FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_SVE) | + ESR_ELx_IL; + unsigned int vq; + + if (guest_hyp_sve_traps_enabled(vcpu)) { + kvm_inject_nested_sync(vcpu, esr); + return true; + } + + if (!p->is_write) { + p->regval = vcpu_read_sys_reg(vcpu, ZCR_EL2); + return true; + } + + vq = SYS_FIELD_GET(ZCR_ELx, LEN, p->regval) + 1; + vq = min(vq, vcpu_sve_max_vq(vcpu)); + vcpu_write_sys_reg(vcpu, vq - 1, ZCR_EL2); + return true; +} + /* * Architected system registers. * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 @@ -2688,6 +2725,9 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG_VNCR(HFGITR_EL2, reset_val, 0), EL2_REG_VNCR(HACR_EL2, reset_val, 0), + { SYS_DESC(SYS_ZCR_EL2), .access = access_zcr_el2, .reset = reset_val, + .visibility = sve_el2_visibility, .reg = ZCR_EL2 }, + EL2_REG_VNCR(HCRX_EL2, reset_val, 0), EL2_REG(TTBR0_EL2, access_rw, reset_val, 0),