From patchwork Tue Sep 3 15:38:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13788954 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 506C8188912; Tue, 3 Sep 2024 15:38:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725377921; cv=none; b=NbaHipuFB74RbBIppjGy7mFILrX6fbvrYFhChL0QvZpeCqmEI+g9cXoyM3qjlujfI0YF4+nd/6ZIL49tl0dtxtxnCFRDeUFg7ZMOEiWu/uE6ny7nLvYBmTqGH5MgMVNRv1fNR5HV2fsRJ0KXgaD59kOMOPuuiMW5yzL2Y41LNOU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725377921; c=relaxed/simple; bh=38G/HWi8wcBRl5YO/Y32Kqhg8KYAnYo3gA4UsZj0qjE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kshc4CtZN7UQqqlVqObp3bUPqzsMKKo3L3qEHK/zWRh1B1op2k4ZfHf3WS7ElBr1lsLm8BjM1dA3oTE7CPy/PKRKHcK9CfW1nWcVxY6TCtIzJltGXpqMKShdpjEegujzU+Cp0O984wYh1hVQEur68AtvpvfTCrdrJos5VsL6kbU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MGugHkII; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MGugHkII" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB6C8C4AF09; Tue, 3 Sep 2024 15:38:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725377921; bh=38G/HWi8wcBRl5YO/Y32Kqhg8KYAnYo3gA4UsZj0qjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MGugHkIIDVDd2j+nqG4AWP2gfJamDoDunncPxYYJXuc7kCAt82FV7UUURhNvKY0Hh uYs4KWJcbUy4WWyX4IKU63Q6il9P7Y8MAe7JtGU6IRa+nSO2W+hyneT1/nmHrr6Cn8 P4+b7bHwyAy5DUPRrw5SnquoAwt2nrWxal6V8AxIImx/ggtLZSVtJtLUk7RQtydW5A XnUQFFEUCU9n2D3OfyXSxSiklSMG9QyqYtVWQHKLuZC0Sv1Lywq65GAC8GgwPVVB5F BoXunN+jdEPOmeLMCcES0mNZ8KN0Yb5bVYW34Lf6tLHJMDpjFQd4FlXvf8x9Nr6W7Q lN5mCuvuaSh3Q== 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 1slVc6-009Hr9-T7; Tue, 03 Sep 2024 16:38:38 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Joey Gouly , Alexandru Elisei , Mark Brown Subject: [PATCH v2 02/16] KVM: arm64: nv: Save/Restore vEL2 sysregs Date: Tue, 3 Sep 2024 16:38:20 +0100 Message-Id: <20240903153834.1909472-3-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240903153834.1909472-1-maz@kernel.org> References: <20240903153834.1909472-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, joey.gouly@arm.com, alexandru.elisei@arm.com, broonie@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Whenever we need to restore the guest's system registers to the CPU, we now need to take care of the EL2 system registers as well. Most of them are accessed via traps only, but some have an immediate effect and also a guest running in VHE mode would expect them to be accessible via their EL1 encoding, which we do not trap. For vEL2 we write the virtual EL2 registers with an identical format directly into their EL1 counterpart, and translate the few registers that have a different format for the same effect on the execution when running a non-VHE guest guest hypervisor. Based on an initial patch from Andre Przywara, rewritten many times since. Reviewed-by: Alexandru Elisei Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 5 +- arch/arm64/kvm/hyp/nvhe/sysreg-sr.c | 2 +- arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 137 ++++++++++++++++++++- 3 files changed, 139 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h index 4c0fdabaf8ae..dfbc0159bf0b 100644 --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h @@ -128,9 +128,10 @@ static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt) write_sysreg(ctxt_sys_reg(ctxt, TPIDRRO_EL0), tpidrro_el0); } -static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt) +static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt, + u64 mpidr) { - write_sysreg(ctxt_sys_reg(ctxt, MPIDR_EL1), vmpidr_el2); + write_sysreg(mpidr, vmpidr_el2); if (has_vhe() || !cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { diff --git a/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c index 29305022bc04..dba101565de3 100644 --- a/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/nvhe/sysreg-sr.c @@ -28,7 +28,7 @@ void __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt) void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt) { - __sysreg_restore_el1_state(ctxt); + __sysreg_restore_el1_state(ctxt, ctxt_sys_reg(ctxt, MPIDR_EL1)); __sysreg_restore_common_state(ctxt); __sysreg_restore_user_state(ctxt); __sysreg_restore_el2_return_state(ctxt); diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c index e12bd7d6d2dc..6db5b4d0f3a4 100644 --- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -15,6 +15,108 @@ #include #include +static void __sysreg_save_vel2_state(struct kvm_cpu_context *ctxt) +{ + /* These registers are common with EL1 */ + ctxt_sys_reg(ctxt, PAR_EL1) = read_sysreg(par_el1); + ctxt_sys_reg(ctxt, TPIDR_EL1) = read_sysreg(tpidr_el1); + + ctxt_sys_reg(ctxt, ESR_EL2) = read_sysreg_el1(SYS_ESR); + ctxt_sys_reg(ctxt, AFSR0_EL2) = read_sysreg_el1(SYS_AFSR0); + ctxt_sys_reg(ctxt, AFSR1_EL2) = read_sysreg_el1(SYS_AFSR1); + ctxt_sys_reg(ctxt, FAR_EL2) = read_sysreg_el1(SYS_FAR); + ctxt_sys_reg(ctxt, MAIR_EL2) = read_sysreg_el1(SYS_MAIR); + ctxt_sys_reg(ctxt, VBAR_EL2) = read_sysreg_el1(SYS_VBAR); + ctxt_sys_reg(ctxt, CONTEXTIDR_EL2) = read_sysreg_el1(SYS_CONTEXTIDR); + ctxt_sys_reg(ctxt, AMAIR_EL2) = read_sysreg_el1(SYS_AMAIR); + + /* + * In VHE mode those registers are compatible between EL1 and EL2, + * and the guest uses the _EL1 versions on the CPU naturally. + * So we save them into their _EL2 versions here. + * For nVHE mode we trap accesses to those registers, so our + * _EL2 copy in sys_regs[] is always up-to-date and we don't need + * to save anything here. + */ + if (__vcpu_el2_e2h_is_set(ctxt)) { + u64 val; + + /* + * We don't save CPTR_EL2, as accesses to CPACR_EL1 + * are always trapped, ensuring that the in-memory + * copy is always up-to-date. A small blessing... + */ + ctxt_sys_reg(ctxt, SCTLR_EL2) = read_sysreg_el1(SYS_SCTLR); + ctxt_sys_reg(ctxt, TTBR0_EL2) = read_sysreg_el1(SYS_TTBR0); + ctxt_sys_reg(ctxt, TTBR1_EL2) = read_sysreg_el1(SYS_TTBR1); + ctxt_sys_reg(ctxt, TCR_EL2) = read_sysreg_el1(SYS_TCR); + + /* + * The EL1 view of CNTKCTL_EL1 has a bunch of RES0 bits where + * the interesting CNTHCTL_EL2 bits live. So preserve these + * bits when reading back the guest-visible value. + */ + val = read_sysreg_el1(SYS_CNTKCTL); + val &= CNTKCTL_VALID_BITS; + ctxt_sys_reg(ctxt, CNTHCTL_EL2) &= ~CNTKCTL_VALID_BITS; + ctxt_sys_reg(ctxt, CNTHCTL_EL2) |= val; + } + + ctxt_sys_reg(ctxt, SP_EL2) = read_sysreg(sp_el1); + ctxt_sys_reg(ctxt, ELR_EL2) = read_sysreg_el1(SYS_ELR); + ctxt_sys_reg(ctxt, SPSR_EL2) = read_sysreg_el1(SYS_SPSR); +} + +static void __sysreg_restore_vel2_state(struct kvm_cpu_context *ctxt) +{ + u64 val; + + /* These registers are common with EL1 */ + write_sysreg(ctxt_sys_reg(ctxt, PAR_EL1), par_el1); + write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL1), tpidr_el1); + + write_sysreg(read_cpuid_id(), vpidr_el2); + write_sysreg(ctxt_sys_reg(ctxt, MPIDR_EL1), vmpidr_el2); + write_sysreg_el1(ctxt_sys_reg(ctxt, MAIR_EL2), SYS_MAIR); + write_sysreg_el1(ctxt_sys_reg(ctxt, VBAR_EL2), SYS_VBAR); + write_sysreg_el1(ctxt_sys_reg(ctxt, CONTEXTIDR_EL2),SYS_CONTEXTIDR); + write_sysreg_el1(ctxt_sys_reg(ctxt, AMAIR_EL2), SYS_AMAIR); + + if (__vcpu_el2_e2h_is_set(ctxt)) { + /* + * In VHE mode those registers are compatible between + * EL1 and EL2. + */ + write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL2), SYS_SCTLR); + write_sysreg_el1(ctxt_sys_reg(ctxt, CPTR_EL2), SYS_CPACR); + write_sysreg_el1(ctxt_sys_reg(ctxt, TTBR0_EL2), SYS_TTBR0); + write_sysreg_el1(ctxt_sys_reg(ctxt, TTBR1_EL2), SYS_TTBR1); + write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL2), SYS_TCR); + write_sysreg_el1(ctxt_sys_reg(ctxt, CNTHCTL_EL2), SYS_CNTKCTL); + } else { + /* + * CNTHCTL_EL2 only affects EL1 when running nVHE, so + * no need to restore it. + */ + val = translate_sctlr_el2_to_sctlr_el1(ctxt_sys_reg(ctxt, SCTLR_EL2)); + write_sysreg_el1(val, SYS_SCTLR); + val = translate_cptr_el2_to_cpacr_el1(ctxt_sys_reg(ctxt, CPTR_EL2)); + write_sysreg_el1(val, SYS_CPACR); + val = translate_ttbr0_el2_to_ttbr0_el1(ctxt_sys_reg(ctxt, TTBR0_EL2)); + write_sysreg_el1(val, SYS_TTBR0); + val = translate_tcr_el2_to_tcr_el1(ctxt_sys_reg(ctxt, TCR_EL2)); + write_sysreg_el1(val, SYS_TCR); + } + + write_sysreg_el1(ctxt_sys_reg(ctxt, ESR_EL2), SYS_ESR); + write_sysreg_el1(ctxt_sys_reg(ctxt, AFSR0_EL2), SYS_AFSR0); + write_sysreg_el1(ctxt_sys_reg(ctxt, AFSR1_EL2), SYS_AFSR1); + write_sysreg_el1(ctxt_sys_reg(ctxt, FAR_EL2), SYS_FAR); + write_sysreg(ctxt_sys_reg(ctxt, SP_EL2), sp_el1); + write_sysreg_el1(ctxt_sys_reg(ctxt, ELR_EL2), SYS_ELR); + write_sysreg_el1(ctxt_sys_reg(ctxt, SPSR_EL2), SYS_SPSR); +} + /* * VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and * pstate, which are handled as part of the el2 return state) on every @@ -66,6 +168,7 @@ void __vcpu_load_switch_sysregs(struct kvm_vcpu *vcpu) { struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt; struct kvm_cpu_context *host_ctxt; + u64 mpidr; host_ctxt = host_data_ptr(host_ctxt); __sysreg_save_user_state(host_ctxt); @@ -89,7 +192,29 @@ void __vcpu_load_switch_sysregs(struct kvm_vcpu *vcpu) */ __sysreg32_restore_state(vcpu); __sysreg_restore_user_state(guest_ctxt); - __sysreg_restore_el1_state(guest_ctxt); + + if (unlikely(__is_hyp_ctxt(guest_ctxt))) { + __sysreg_restore_vel2_state(guest_ctxt); + } else { + if (vcpu_has_nv(vcpu)) { + /* + * Only set VPIDR_EL2 for nested VMs, as this is the + * only time it changes. We'll restore the MIDR_EL1 + * view on put. + */ + write_sysreg(ctxt_sys_reg(guest_ctxt, VPIDR_EL2), vpidr_el2); + + /* + * As we're restoring a nested guest, set the value + * provided by the guest hypervisor. + */ + mpidr = ctxt_sys_reg(guest_ctxt, VMPIDR_EL2); + } else { + mpidr = ctxt_sys_reg(guest_ctxt, MPIDR_EL1); + } + + __sysreg_restore_el1_state(guest_ctxt, mpidr); + } vcpu_set_flag(vcpu, SYSREGS_ON_CPU); } @@ -112,12 +237,20 @@ void __vcpu_put_switch_sysregs(struct kvm_vcpu *vcpu) host_ctxt = host_data_ptr(host_ctxt); - __sysreg_save_el1_state(guest_ctxt); + if (unlikely(__is_hyp_ctxt(guest_ctxt))) + __sysreg_save_vel2_state(guest_ctxt); + else + __sysreg_save_el1_state(guest_ctxt); + __sysreg_save_user_state(guest_ctxt); __sysreg32_save_state(vcpu); /* Restore host user state */ __sysreg_restore_user_state(host_ctxt); + /* If leaving a nesting guest, restore MPIDR_EL1 default view */ + if (vcpu_has_nv(vcpu)) + write_sysreg(read_cpuid_id(), vpidr_el2); + vcpu_clear_flag(vcpu, SYSREGS_ON_CPU); }