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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 03DD8C54E76 for ; Mon, 20 Nov 2023 14:15:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=TfIEdI0V4u//GwHQ1qe5Xchcrfb7WqVU8iEZBqSsH1c=; b=WysvfKiK+WVFbt EEYjd9A1ARfo/8RWrBLafWxfC6vPmcsiYi6ENlzmx3FXxScK0hwfHOTxLfhSLk4szJRPp74HXPSZq iowb2GnfrzQr9It5l72/mpn1oUuoxBc8rgpRRKAfXS/PomlReay2slACSYXBaBnA/eOiHW7w8L5z6 QuEtCvucANd2ZPUYo7XaZ3Tb4l8TiXt4nCwgViMjvZFML2EsJ5KVvO0LOGtxzXuEPiD+u1HRQUm7j b84uGTomtG/B71Ndr6Hnow2ZIYjac0wiwfVGhSKe7fReE9wNnoBpVjJs7h+KjoIw4QBez5ZrZ43Gv ALG3v6rWFb9nBMSf48Tw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r553i-00CFMM-02; Mon, 20 Nov 2023 14:15:30 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r543D-00C4dN-1b for linux-arm-kernel@lists.infradead.org; Mon, 20 Nov 2023 13:10:58 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id C6AD661269; Mon, 20 Nov 2023 13:10:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7668DC433AB; Mon, 20 Nov 2023 13:10:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700485853; bh=CZhhXZ8QKNznTktBE86rbHLYtD+3fHcym+v/429FNkk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P3Vkzip52fMIzd4T+Dx+HYtoXn7B0WFsmWgzBVQ5bV5AHf3WEg4Z3UmqGHZropyQc JcgjtT4WK8jNSUpir85/165UuGZr6ZpKyLL/GAV5CT92tZ6FwDKTEHy7PCrCqnAKbo ZzBSMsIlMLgh2XKu1+eKAgVJB8HcTM/JMOBMXCpUulfcHrLSKO2KJCTbEArkFxvzzq sIcItqnYVAIKoFLGfbkDcBWoqqSROy9kPPxCPbwiDoGqk/zcuCWWn96YlE5BRP1Ras bgca4syx6TGQlUb2XozFMHGlrr2SXp6s/T6ZlrAuwh0g7GkyeOS5lc+BRmw+vAi7nl jzrTzICihuLkw== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1r5439-00EjnU-Jh; Mon, 20 Nov 2023 13:10:51 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Alexandru Elisei , Andre Przywara , Chase Conklin , Christoffer Dall , Ganapatrao Kulkarni , Darren Hart , Jintack Lim , Russell King , Miguel Luis , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH v11 10/43] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() Date: Mon, 20 Nov 2023 13:09:54 +0000 Message-Id: <20231120131027.854038-11-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231120131027.854038-1-maz@kernel.org> References: <20231120131027.854038-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alexandru.elisei@arm.com, andre.przywara@arm.com, chase.conklin@arm.com, christoffer.dall@arm.com, gankulkarni@os.amperecomputing.com, darren@os.amperecomputing.com, jintack@cs.columbia.edu, rmk+kernel@armlinux.org.uk, miguel.luis@oracle.com, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231120_051055_962970_A6ED91FD X-CRM114-Status: GOOD ( 24.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org KVM internally uses accessor functions when reading or writing the guest's system registers. This takes care of accessing either the stored copy or using the "live" EL1 system registers when the host uses VHE. With the introduction of virtual EL2 we add a bunch of EL2 system registers, which now must also be taken care of: - If the guest is running in vEL2, and we access an EL1 sysreg, we must revert to the stored version of that, and not use the CPU's copy. - If the guest is running in vEL1, and we access an EL2 sysreg, we must also use the stored version, since the CPU carries the EL1 copy. - Some EL2 system registers are supposed to affect the current execution of the system, so we need to put them into their respective EL1 counterparts. For this we need to define a mapping between the two. - Some EL2 system registers have a different format than their EL1 counterpart, so we need to translate them before writing them to the CPU. This is done using an (optional) translate function in the map. All of these cases are now wrapped into the existing accessor functions, so KVM users wouldn't need to care whether they access EL2 or EL1 registers and also which state the guest is in. Reviewed-by: Ganapatrao Kulkarni Reviewed-by: Alexandru Elisei Reviewed-by: Russell King (Oracle) Co-developed-by: Andre Przywara Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/sys_regs.c | 129 ++++++++++++++++++++++++++++-- 2 files changed, 126 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 9e8cd2bb95c3..f17fb7c42973 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -907,6 +907,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) case AMAIR_EL1: *val = read_sysreg_s(SYS_AMAIR_EL12); break; case CNTKCTL_EL1: *val = read_sysreg_s(SYS_CNTKCTL_EL12); break; case ELR_EL1: *val = read_sysreg_s(SYS_ELR_EL12); break; + case SPSR_EL1: *val = read_sysreg_s(SYS_SPSR_EL12); break; case PAR_EL1: *val = read_sysreg_par(); break; case DACR32_EL2: *val = read_sysreg_s(SYS_DACR32_EL2); break; case IFSR32_EL2: *val = read_sysreg_s(SYS_IFSR32_EL2); break; @@ -951,6 +952,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) case AMAIR_EL1: write_sysreg_s(val, SYS_AMAIR_EL12); break; case CNTKCTL_EL1: write_sysreg_s(val, SYS_CNTKCTL_EL12); break; case ELR_EL1: write_sysreg_s(val, SYS_ELR_EL12); break; + case SPSR_EL1: write_sysreg_s(val, SYS_SPSR_EL12); break; case PAR_EL1: write_sysreg_s(val, SYS_PAR_EL1); break; case DACR32_EL2: write_sysreg_s(val, SYS_DACR32_EL2); break; case IFSR32_EL2: write_sysreg_s(val, SYS_IFSR32_EL2); break; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index c31fddc1591d..92bb91e520a8 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -72,24 +72,143 @@ static bool write_to_read_only(struct kvm_vcpu *vcpu, "sys_reg write to read-only register"); } +#define PURE_EL2_SYSREG(el2) \ + case el2: { \ + *el1r = el2; \ + return true; \ + } + +#define MAPPED_EL2_SYSREG(el2, el1, fn) \ + case el2: { \ + *xlate = fn; \ + *el1r = el1; \ + return true; \ + } + +static bool get_el2_to_el1_mapping(unsigned int reg, + unsigned int *el1r, u64 (**xlate)(u64)) +{ + switch (reg) { + PURE_EL2_SYSREG( VPIDR_EL2 ); + PURE_EL2_SYSREG( VMPIDR_EL2 ); + PURE_EL2_SYSREG( ACTLR_EL2 ); + PURE_EL2_SYSREG( HCR_EL2 ); + PURE_EL2_SYSREG( MDCR_EL2 ); + PURE_EL2_SYSREG( HSTR_EL2 ); + PURE_EL2_SYSREG( HACR_EL2 ); + PURE_EL2_SYSREG( VTTBR_EL2 ); + PURE_EL2_SYSREG( VTCR_EL2 ); + PURE_EL2_SYSREG( RVBAR_EL2 ); + PURE_EL2_SYSREG( TPIDR_EL2 ); + PURE_EL2_SYSREG( HPFAR_EL2 ); + PURE_EL2_SYSREG( CNTHCTL_EL2 ); + MAPPED_EL2_SYSREG(SCTLR_EL2, SCTLR_EL1, + translate_sctlr_el2_to_sctlr_el1 ); + MAPPED_EL2_SYSREG(CPTR_EL2, CPACR_EL1, + translate_cptr_el2_to_cpacr_el1 ); + MAPPED_EL2_SYSREG(TTBR0_EL2, TTBR0_EL1, + translate_ttbr0_el2_to_ttbr0_el1 ); + MAPPED_EL2_SYSREG(TTBR1_EL2, TTBR1_EL1, NULL ); + MAPPED_EL2_SYSREG(TCR_EL2, TCR_EL1, + translate_tcr_el2_to_tcr_el1 ); + MAPPED_EL2_SYSREG(VBAR_EL2, VBAR_EL1, NULL ); + MAPPED_EL2_SYSREG(AFSR0_EL2, AFSR0_EL1, NULL ); + MAPPED_EL2_SYSREG(AFSR1_EL2, AFSR1_EL1, NULL ); + MAPPED_EL2_SYSREG(ESR_EL2, ESR_EL1, NULL ); + MAPPED_EL2_SYSREG(FAR_EL2, FAR_EL1, NULL ); + MAPPED_EL2_SYSREG(MAIR_EL2, MAIR_EL1, NULL ); + MAPPED_EL2_SYSREG(AMAIR_EL2, AMAIR_EL1, NULL ); + MAPPED_EL2_SYSREG(ELR_EL2, ELR_EL1, NULL ); + MAPPED_EL2_SYSREG(SPSR_EL2, SPSR_EL1, NULL ); + default: + return false; + } +} + u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) { u64 val = 0x8badf00d8badf00d; + u64 (*xlate)(u64) = NULL; + unsigned int el1r; + + if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU)) + goto memory_read; - if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && - __vcpu_read_sys_reg_from_cpu(reg, &val)) + if (unlikely(get_el2_to_el1_mapping(reg, &el1r, &xlate))) { + if (!is_hyp_ctxt(vcpu)) + goto memory_read; + + /* + * If this register does not have an EL1 counterpart, + * then read the stored EL2 version. + */ + if (reg == el1r) + goto memory_read; + + /* + * If we have a non-VHE guest and that the sysreg + * requires translation to be used at EL1, use the + * in-memory copy instead. + */ + if (!vcpu_el2_e2h_is_set(vcpu) && xlate) + goto memory_read; + + /* Get the current version of the EL1 counterpart. */ + WARN_ON(!__vcpu_read_sys_reg_from_cpu(el1r, &val)); + return val; + } + + /* EL1 register can't be on the CPU if the guest is in vEL2. */ + if (unlikely(is_hyp_ctxt(vcpu))) + goto memory_read; + + if (__vcpu_read_sys_reg_from_cpu(reg, &val)) return val; +memory_read: return __vcpu_sys_reg(vcpu, reg); } void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { - if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && - __vcpu_write_sys_reg_to_cpu(val, reg)) + u64 (*xlate)(u64) = NULL; + unsigned int el1r; + + if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU)) + goto memory_write; + + if (unlikely(get_el2_to_el1_mapping(reg, &el1r, &xlate))) { + if (!is_hyp_ctxt(vcpu)) + goto memory_write; + + /* + * Always store a copy of the write to memory to avoid having + * to reverse-translate virtual EL2 system registers for a + * non-VHE guest hypervisor. + */ + __vcpu_sys_reg(vcpu, reg) = val; + + /* No EL1 counterpart? We're done here.? */ + if (reg == el1r) + return; + + if (!vcpu_el2_e2h_is_set(vcpu) && xlate) + val = xlate(val); + + /* Redirect this to the EL1 version of the register. */ + WARN_ON(!__vcpu_write_sys_reg_to_cpu(val, el1r)); + return; + } + + /* EL1 register can't be on the CPU if the guest is in vEL2. */ + if (unlikely(is_hyp_ctxt(vcpu))) + goto memory_write; + + if (__vcpu_write_sys_reg_to_cpu(val, reg)) return; - __vcpu_sys_reg(vcpu, reg) = val; +memory_write: + __vcpu_sys_reg(vcpu, reg) = val; } /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel