From mboxrd@z Thu Jan 1 00:00:00 1970 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 CE19F101C7 for ; Tue, 8 Aug 2023 11:47:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EE06C433CD; Tue, 8 Aug 2023 11:47:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691495275; bh=Y+sCX9NjKo50qL0UVZVq/hehTymL/TV6ZrGWTgDRqM0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SBZ3+bkQyXhsDuGeReXx9NyuG1CQqJxW33C0s+necZx0EeKJO3e6/JMxLcCTZM7Vl kT28vGPEnsdpN/jKfCDJg5aA0dz123Utm+g6Pe8gY0ytLOWk97MeVd103g+Nf1PuTE XAy7u0WqapiFkmSso06wHHYc7+RUOiLAvazB7ZMA1ckAg+LFz0KBcx5N5XD9Bs23I9 kOCMA5lbBmFNxW88F3B4VCOw2YaBfru7xqYLTE57MIYsHydWvzyU7R340NZgnqS8OW PBgRc2UVvxX9pYarXLfsUYKtyesRoE6+MyRVpWbDCsVq2tY4oNM4Urkmybyhdjj7mD pbVE6RiSbv1cg== 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 1qTLBN-0037Ph-3p; Tue, 08 Aug 2023 12:47:26 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Catalin Marinas , Eric Auger , Mark Brown , Mark Rutland , Will Deacon , Alexandru Elisei , Andre Przywara , Chase Conklin , Ganapatrao Kulkarni , Darren Hart , Miguel Luis , James Morse , Suzuki K Poulose , Oliver Upton , Zenghui Yu Subject: [PATCH v3 26/27] KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systems Date: Tue, 8 Aug 2023 12:47:10 +0100 Message-Id: <20230808114711.2013842-27-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230808114711.2013842-1-maz@kernel.org> References: <20230808114711.2013842-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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, catalin.marinas@arm.com, eric.auger@redhat.com, broonie@kernel.org, mark.rutland@arm.com, will@kernel.org, alexandru.elisei@arm.com, andre.przywara@arm.com, chase.conklin@arm.com, gankulkarni@os.amperecomputing.com, darren@os.amperecomputing.com, 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 Although the nVHE behaviour requires HCRX_EL2 to be switched on each switch between host and guest, there is nothing in this register that would affect a VHE host. It is thus possible to save/restore this register on load/put on VHE systems, avoiding unnecessary sysreg access on the hot path. Additionally, it avoids unnecessary traps when running with NV. To achieve this, simply move the read/writes to the *_common() helpers, which are called on load/put on VHE, and more eagerly on nVHE. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/include/hyp/switch.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index a4750070563f..060c5a0409e5 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -197,6 +197,9 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu) vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2); write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); + if (cpus_have_final_cap(ARM64_HAS_HCX)) + write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2); + __activate_traps_hfgxtr(vcpu); } @@ -213,6 +216,9 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU); } + if (cpus_have_final_cap(ARM64_HAS_HCX)) + write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2); + __deactivate_traps_hfgxtr(vcpu); } @@ -227,9 +233,6 @@ static inline void ___activate_traps(struct kvm_vcpu *vcpu) if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE)) write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2); - - if (cpus_have_final_cap(ARM64_HAS_HCX)) - write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2); } static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) @@ -244,9 +247,6 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 &= ~HCR_VSE; vcpu->arch.hcr_el2 |= read_sysreg(hcr_el2) & HCR_VSE; } - - if (cpus_have_final_cap(ARM64_HAS_HCX)) - write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2); } static inline bool __populate_fault_info(struct kvm_vcpu *vcpu) -- 2.34.1