From patchwork Sat Feb 15 15:01:32 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13976142 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5238C021A0 for ; Sat, 15 Feb 2025 15:15:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=255aD0tukRNCUFSVEx/lxc/CBZ7ChZ9/Iol1CL1A7hc=; b=cT9k9Zn9weJ1/zfJSTD+334vuM NAU4Uu3rb4bBYoj4HQ+qRhuAbwszy6RzKO6pWg2I3JEStwLT4ITnv1cooJVqCS23iS/51L2h7cAEc vW/wFj5vGb5WH7LSDVkn+SECTI4L/UGOIQiQiEihU4lqKL5N3FjtzG8INyyH+pRc3F53VO54FKr3U hWT1ZT1tev+GxRASloVAJmzhFyaKdLTZ+NofzMANHsW/noRLAxzSl7KgXAlGZSt2Vw2Ys5oH82DbN qGHSNAUsMGngsdYw6RLTSFTftn0cTQNf6yX+D7H2MU9tAIYJG2hwfok3z3lEa5jnrD6nRumAcLOHD 9CcBHeZQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tjJt1-00000000IhO-0U4t; Sat, 15 Feb 2025 15:15:19 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tjJgE-00000000H3T-2vaF for linux-arm-kernel@lists.infradead.org; Sat, 15 Feb 2025 15:02:08 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 395235C545F; Sat, 15 Feb 2025 15:01:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74410C4CEF4; Sat, 15 Feb 2025 15:02:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739631724; bh=NMYKJ0yMl3LarmDuWH+JZqyMOz1yxAJw5qnSKOyFiDw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kEhvtf+Dwp4sEMZQBs4Zxno6Cose3p/fhabVE2663xjUnHGsXJVdFU5/t4Nt2K4MU NNHbEU+tqkpAE0MC7tjydH91/bryxA4JpnLNp6Y0PIV3Zv9KT1NaFxFw+SCTvaf6Fu nXNg+NnEMiK9t+yleIkz3vnqHxo/OEjhD3l5VYyKuz/41jmxHwSRg8UBfqCQYtDV94 F95MEBfWUvV8oKnu6gz9461peOvLcj8CRL/gT/w/VzKnaCAeBhjkAAYceFzQxq6iwo wFyUcmX4ufl9LSRCW+uLJRXnVcHmnH6lGtmB6jCVABcF3i49iA1mTqdjc2CGZfgxco CRQ2RHa8feVmg== 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 1tjJgA-004Nz6-Hw; Sat, 15 Feb 2025 15:02:02 +0000 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 12/14] KVM: arm64: nv: Program host's VNCR_EL2 to the fixmap address Date: Sat, 15 Feb 2025 15:01:32 +0000 Message-Id: <20250215150134.3765791-13-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250215150134.3765791-1-maz@kernel.org> References: <20250215150134.3765791-1-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-20250215_070206_836516_0FFC4FAD X-CRM114-Status: GOOD ( 15.00 ) 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 3453fb76cf0e3..6242ab037bfdf 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)