From patchwork Mon Feb 19 09:20:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13562411 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 07A732420C; Mon, 19 Feb 2024 09:20:25 +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=1708334425; cv=none; b=Bf4XYA9TB/xkC26rb3Pob9eiR8dQBcExyICQ2k0Od4SMiwEt172tXD3fnSwhQ4J9ik7NAuY1z0xJkkih1YMoA/kLhkzgFFUFdHJEwN9uJ34li6JRYTMKI0HbMlaFUdx20LfOmDBJ6GATWqdbdcNcPE4oBaottvK523wls9aC2v4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708334425; c=relaxed/simple; bh=8mefTCTGskrcvQkNMN6umnAmckW2kWR8W3YQ9pAOy6A=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XKO7ybSigyrhlTVg0s7K0EfYin6UF31u5a2duqmegWno2nM54yb4vhjnnofQHN9NRPbE4RkhFp5TiIVe9NjEfBZYQz/gHGM5bXD1Ybb2HUoatvLR93z4yaaFV+zykjTmrCBaaXYbP5QH9Q1S/ibEteK66DZfx/3VaKqenC01vNU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KwmZChOS; 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="KwmZChOS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8D53C433B1; Mon, 19 Feb 2024 09:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708334424; bh=8mefTCTGskrcvQkNMN6umnAmckW2kWR8W3YQ9pAOy6A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KwmZChOSorNCUKmU35Kl15KCa/EtcaIybpy5x+xy5ixqtoqGYSsGpIbaX3IXiRRNA ekodWPbrQ/WLMSRdtP2hir2yZbaBvSzerY+G9k91XFCrl7/Wp5s2tpDs6w8NWgmUFg qekThJTZD+O0Kjc2WtKJj1Jhbxa2oUHT2llIeegDvluHfYPG4NKbd5MM/h/U4xyAKX w0rGNm72fH8lQA6OVwekof6ZIJGWZH+hZMWuJQx2FM1amoVw2M8PG2qWXAqU3jDljC aIIPXeaFrKORUDmaqlfxjy2b9SLn9lXPo0jTBI29gwYy4XWoH3yAzxS1wPfKLdWZEO VafRY0lQ6AGrg== 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 1rbzp0-004WBZ-Uz; Mon, 19 Feb 2024 09:20:23 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Will Deacon , Catalin Marinas Subject: [PATCH 08/13] KVM: arm64: nv: Handle HCR_EL2.{API,APK} independantly Date: Mon, 19 Feb 2024 09:20:09 +0000 Message-Id: <20240219092014.783809-9-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240219092014.783809-1-maz@kernel.org> References: <20240219092014.783809-1-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, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, will@kernel.org, catalin.marinas@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Although KVM couples API and APK for simplicity, the architecture makes no such requirement, and the two can be independently set or cleared. Check for which of the two possible reasons we have trapped here, and if the corresponding L1 control bit isn't set, delegate the handling for forwarding. Otherwise, set this exact bit in HCR_EL2 and resume the guest. Of course, in the non-NV case, we keep setting both bits and be done with it. Note that the entry core already saves/restores the keys should any of the two control bits be set. This result in a bit of rework, and the removal of the (trivial) vcpu_ptrauth_enable() helper. Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_emulate.h | 5 ---- arch/arm64/kvm/hyp/include/hyp/switch.h | 32 +++++++++++++++++++++---- 2 files changed, 27 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index debc3753d2ef..d2177bc77844 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -125,11 +125,6 @@ static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_TWI; } -static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu) -{ - vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK); -} - static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu) { vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK); diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index f5f701f309a9..a0908d7a8f56 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -480,11 +480,35 @@ DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) { struct kvm_cpu_context *ctxt; - u64 val; + u64 enable = 0; if (!vcpu_has_ptrauth(vcpu)) return false; + /* + * NV requires us to handle API and APK independently, just in + * case the hypervisor is totally nuts. Please barf >here<. + */ + if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) { + switch (ESR_ELx_EC(kvm_vcpu_get_esr(vcpu))) { + case ESR_ELx_EC_PAC: + if (!(__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_API)) + return false; + + enable |= HCR_API; + break; + + case ESR_ELx_EC_SYS64: + if (!(__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_APK)) + return false; + + enable |= HCR_APK; + break; + } + } else { + enable = HCR_API | HCR_APK; + } + ctxt = this_cpu_ptr(&kvm_hyp_ctxt); __ptrauth_save_key(ctxt, APIA); __ptrauth_save_key(ctxt, APIB); @@ -492,11 +516,9 @@ static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code) __ptrauth_save_key(ctxt, APDB); __ptrauth_save_key(ctxt, APGA); - vcpu_ptrauth_enable(vcpu); - val = read_sysreg(hcr_el2); - val |= (HCR_API | HCR_APK); - write_sysreg(val, hcr_el2); + vcpu->arch.hcr_el2 |= enable; + sysreg_clear_set(hcr_el2, 0, enable); return true; }