From patchwork Wed May 29 14:56:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 13679061 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 667F3180A85; Wed, 29 May 2024 14:56:36 +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=1716994596; cv=none; b=LCEVWITd435kmuxTRphbP4ao5QTi7RYjX7Dauf38bO4mJle20dpvSxoN1TCtmb69oe9j1D08TStX00f76JO0cU3VU9sNPcOWxQPIWgQyX9ph7TfXkXZTeRDHCbrUGPkTE/7YdwWAQowd3T4q0WmB9aeYQnX3paJCOaZAebmKHn8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716994596; c=relaxed/simple; bh=lalKgPn9aCZymbZ6rBD61VGvcDx/j4gQIjnaQmLtLyg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pLGrUY2wGQz/g1xlcBlLlLXVSRFbqNszSq+Vh98e2LCiCwVkhdpUFr6yaLlBp+6umOa3F8w7yat/U48XHso3NZQ+qXK+UVM2Kk8tP6IriERmbtFTTUcdP2vMjjQgDEnJ7JKJsHEDI40uswoXglTuUnlLdkOR4CP2DFazkK/o4aQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fwiU/tww; 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="fwiU/tww" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B443C113CC; Wed, 29 May 2024 14:56:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716994596; bh=lalKgPn9aCZymbZ6rBD61VGvcDx/j4gQIjnaQmLtLyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fwiU/twwjL+Vb8YoJ72X2MQLV/tiWin3bPSMXbotpFy24m8LIwLhv9V62B8xSvxZn pyeD7oN3KNXnCV2mZP8K6sZGWU6tiOWppFm3NjjqW/iQGX5Vomdb2pFtIB3NfruUs2 uf45Mz8tGRWfJEHYj0yAGkWvEaQjCo080t//4GwaMQyvvBjxCpHpMs9/vfPoE8wLrn o3KEJ6V+TIuES8bvIWNL7Ov3Cpg/LKt3a5eXDtEB35HQFQT+kQCVnASFufE1RzJSGG vEkAKBgNDIWihdsP1A5dCTlsvVEAyQjuFWV0NSBk/DU5TiCJLRta1JgwV7I42gCRhC CCqGNYNJntmqA== 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 1sCKjC-00GekF-Ip; Wed, 29 May 2024 15:56:34 +0100 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 , Joey Gouly , Alexandru Elisei , Christoffer Dall , Ganapatrao Kulkarni Subject: [PATCH v2 13/16] KVM: arm64: nv: Invalidate TLBs based on shadow S2 TTL-like information Date: Wed, 29 May 2024 15:56:25 +0100 Message-Id: <20240529145628.3272630-14-maz@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240529145628.3272630-1-maz@kernel.org> References: <20240529145628.3272630-1-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, joey.gouly@arm.com, alexandru.elisei@arm.com, christoffer.dall@arm.com, gankulkarni@os.amperecomputing.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false In order to be able to make S2 TLB invalidations more performant on NV, let's use a scheme derived from the FEAT_TTL extension. If bits [56:55] in the leaf descriptor translating the address in the corresponding shadow S2 are non-zero, they indicate a level which can be used as an invalidation range. This allows further reduction of the systematic over-invalidation that takes place otherwise. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/nested.c | 83 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 82 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 8570b5bd0289..5ab5c43c571b 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -4,6 +4,7 @@ * Author: Jintack Lim */ +#include #include #include @@ -421,12 +422,92 @@ static unsigned int ttl_to_size(u8 ttl) return max_size; } +/* + * Compute the equivalent of the TTL field by parsing the shadow PT. The + * granule size is extracted from the cached VTCR_EL2.TG0 while the level is + * retrieved from first entry carrying the level as a tag. + */ +static u8 get_guest_mapping_ttl(struct kvm_s2_mmu *mmu, u64 addr) +{ + u64 tmp, sz = 0, vtcr = mmu->tlb_vtcr; + kvm_pte_t pte; + u8 ttl, level; + + switch (vtcr & VTCR_EL2_TG0_MASK) { + case VTCR_EL2_TG0_4K: + ttl = (TLBI_TTL_TG_4K << 2); + break; + case VTCR_EL2_TG0_16K: + ttl = (TLBI_TTL_TG_16K << 2); + break; + case VTCR_EL2_TG0_64K: + default: /* IMPDEF: treat any other value as 64k */ + ttl = (TLBI_TTL_TG_64K << 2); + break; + } + + tmp = addr; + +again: + /* Iteratively compute the block sizes for a particular granule size */ + switch (vtcr & VTCR_EL2_TG0_MASK) { + case VTCR_EL2_TG0_4K: + if (sz < SZ_4K) sz = SZ_4K; + else if (sz < SZ_2M) sz = SZ_2M; + else if (sz < SZ_1G) sz = SZ_1G; + else sz = 0; + break; + case VTCR_EL2_TG0_16K: + if (sz < SZ_16K) sz = SZ_16K; + else if (sz < SZ_32M) sz = SZ_32M; + else sz = 0; + break; + case VTCR_EL2_TG0_64K: + default: /* IMPDEF: treat any other value as 64k */ + if (sz < SZ_64K) sz = SZ_64K; + else if (sz < SZ_512M) sz = SZ_512M; + else sz = 0; + break; + } + + if (sz == 0) + return 0; + + tmp &= ~(sz - 1); + if (kvm_pgtable_get_leaf(mmu->pgt, tmp, &pte, NULL)) + goto again; + if (!(pte & PTE_VALID)) + goto again; + level = FIELD_GET(KVM_NV_GUEST_MAP_SZ, pte); + if (!level) + goto again; + + ttl |= level; + + /* + * We now have found some level information in the shadow S2. Check + * that the resulting range is actually including the original IPA. + */ + sz = ttl_to_size(ttl); + if (addr < (tmp + sz)) + return ttl; + + return 0; +} + unsigned long compute_tlb_inval_range(struct kvm_s2_mmu *mmu, u64 val) { + struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu); unsigned long max_size; u8 ttl; - ttl = FIELD_GET(GENMASK_ULL(47, 44), val); + ttl = FIELD_GET(TLBI_TTL_MASK, val); + + if (!ttl || !kvm_has_feat(kvm, ID_AA64MMFR2_EL1, TTL, IMP)) { + /* No TTL, check the shadow S2 for a hint */ + u64 addr = (val & GENMASK_ULL(35, 0)) << 12; + ttl = get_guest_mapping_ttl(mmu, addr); + } max_size = ttl_to_size(ttl);