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t=1744109561; bh=ydvZE2fcKiHSXxy2PEWqOT/2J5DSfX2LWTaD8LM7MhU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p6EQqhUbjihCw38r8bJlIz/jQWNYrmqWPIph4sFf8VkH2AyZAO9Hxv3xLW8z2wWF5 qglkD09LyTxd/SayrAyYOoHMgF2a192LO+/PJQb6eQtYNiRPtTcK9CV/jQV5br0/NY ZG2EUwaUpd8NXWFTURjlrcrwGiTtq7OvcqVBjv8uIF+Qc7fynRHTq1LqCSXqyf0bPZ z4yuRz6Lr3SsMqowkEKU8kQiuNfQvM2qpWuE5BR5fjv6iO59BhxSl6P97xxLTukPBD rMIGzX5Ic6njY+A2i2Kypnp6TA8VS5TBugaVEYbowxmnL9K0Lft98wXiPmKF9GT4nt doJ3ksJg+tPoA== 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 1u26ZL-003QX2-Ac; Tue, 08 Apr 2025 11:52:39 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Eric Auger Subject: [PATCH v2 12/17] KVM: arm64: nv: Program host's VNCR_EL2 to the fixmap address Date: Tue, 8 Apr 2025 11:52:20 +0100 Message-Id: <20250408105225.4002637-13-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250408105225.4002637-1-maz@kernel.org> References: <20250408105225.4002637-1-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, joey.gouly@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, eric.auger@redhat.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-20250408_115244_357993_61A07A0F X-CRM114-Status: GOOD ( 16.15 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Since we now have a way to map the guest's VNCR_EL2 on the host, we can point the host's VNCR_EL2 to it and go full circle! Note that we unconditionally assign the fixmap to VNCR_EL2, irrespective of the guest's version being mapped or not. We want to take a fault on first access, so the fixmap either contains something guranteed to be either invalid or a guest mapping. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/vhe/switch.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 220dee8a45e0d..5eaff1ae32b29 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -48,6 +48,7 @@ DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); static u64 __compute_hcr(struct kvm_vcpu *vcpu) { + u64 guest_hcr = __vcpu_sys_reg(vcpu, HCR_EL2); u64 hcr = vcpu->arch.hcr_el2; if (!vcpu_has_nv(vcpu)) @@ -70,9 +71,23 @@ static u64 __compute_hcr(struct kvm_vcpu *vcpu) write_sysreg_s(vcpu->arch.ctxt.vncr_array, SYS_VNCR_EL2); } else { host_data_clear_flag(VCPU_IN_HYP_CONTEXT); + + if (guest_hcr & HCR_NV) { + u64 va = __fix_to_virt(vncr_fixmap(smp_processor_id())); + + /* Inherit the low bits from the actual register */ + va |= __vcpu_sys_reg(vcpu, VNCR_EL2) & GENMASK(PAGE_SHIFT - 1, 0); + write_sysreg_s(va, SYS_VNCR_EL2); + + /* Force NV2 in case the guest is forgetful... */ + guest_hcr |= HCR_NV2; + } } - return hcr | (__vcpu_sys_reg(vcpu, HCR_EL2) & ~NV_HCR_GUEST_EXCLUDE); + BUG_ON(host_data_test_flag(VCPU_IN_HYP_CONTEXT) && + host_data_test_flag(L1_VNCR_MAPPED)); + + return hcr | (guest_hcr & ~NV_HCR_GUEST_EXCLUDE); } static void __activate_cptr_traps(struct kvm_vcpu *vcpu)