From patchwork Tue Aug 13 14:47:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13762156 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 40C6419FA8A; Tue, 13 Aug 2024 14:47:58 +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=1723560479; cv=none; b=fw2LG/23uycEaERuJBT6wzRAZ3dR++RTQdoN9SJaXowsLnOpcJbrtrC5RjyeSa5jQVkLkK25tiiSyyx4WTwhO8RnqH3EWZX5Fu4/gXlPMlWEjIfeeZytRvi0OMTH/RhubRlNqLqrq30dfyIC3qWbxup6UY+AvVhCFF9xTrZm/Cc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723560479; c=relaxed/simple; bh=38G/HWi8wcBRl5YO/Y32Kqhg8KYAnYo3gA4UsZj0qjE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=U/INxgWCCxJhDGGiYIvsEW7cNlLVWmCeHyFVfLID8IqaCt0zD5SA42qXXuoB8x0fU/BiBTCJqb8S1RIkVRBd208XMVmrU9CXg54d+qRbE/zkA2BHNIihITDmud443jPKuj3+hZygr0fylJqDqnrmYvra/qTk8MY7246WhfpDM0g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=go0FWEf7; 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="go0FWEf7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2E25C4AF11; Tue, 13 Aug 2024 14:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723560478; bh=38G/HWi8wcBRl5YO/Y32Kqhg8KYAnYo3gA4UsZj0qjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=go0FWEf7PwrN6nLHezhEUUScwaRuGg+s1Ss6mEUbE2f7GJB+QUDpW8SXVSslh4FBo gr/AxT0Pue01ICbXGcjUWPLS4GaNFSWF5CDkITHVrykDzPGtE6TzXnCJ94djqtqf9i rZLolaFVa9Tzlc/P8hFON1/vWlZUO8aav2s9DEbCA0EIOAo8T/itONPMCerLNdZfrK CRtwZxUkZAPL+mdp1cilB9iBhQFnNlDa0bUNT1THfeE8OBqP+1B3k/EwTax25F05uB xlbaNr7a9gF78MBk6RSGhFE6dA3NehGI38SpS4iZstYMUFuydt3oXHHZF48OnIJrZh RcLjb8fTNk9bg== 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 1sdsoV-003O27-JD; Tue, 13 Aug 2024 15:47:56 +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 Subject: [PATCH 02/10] KVM: arm64: nv: Save/Restore vEL2 sysregs Date: Tue, 13 Aug 2024 15:47:30 +0100 Message-Id: <20240813144738.2048302-3-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240813144738.2048302-1-maz@kernel.org> References: <20240813144738.2048302-1-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 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); }