From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.177 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793624512; b=ErBFTUCiQSYlka3mAesJGyaTXrBh+HpHyDdSXljGVegzDa/qlna98frhaIiIAwl3o8Es lMNGrvvjYE1QsIQRvkCPC7GFtBvzcYqSdnFIEgClBtUNyw+dibjJR8BqjkLzH09uP8eeN 6wHB4CeKT32ux/kpIDeyfYk53YgpMkDLHoDCmcEZglEdfNl40We071lXdrNYL2vLlahj0 fSvUOu6zNbIypze5XSHM8C3iLenHRanfsI9sZMJ+oGTjG8Pw25QQRxcGwlAVM45CSDmFQ j/QK+VG3FDM11S4NtYo3Xe3qmgytqaRWF5L6FpvBhXLidBZc9OCpEGiKeveHB3+6l4A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793624512; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=vzUCBfEqZA71dS3jLvdXgp0iBiHaOT4PnmGdXf9hgiI=; b=EhVDu7/CccNdE5K6Qqka3d62OA5M2UYacUQSrgfOgbN37AMVjXMJnHsAgMgCUFpejnou 84R9VxzSweDrOUk2MvjYSpGlGTFddfG6+9LpZTbh511uU/NyCEeTj6aKmQlpJ2m9EYU7/ lscW2xr3xEdzEI3wQ+7jDXL53kkyhmT6EGEwS1SxA28jYEwm1K6Xw9BCinwsdo/S9yJ2t t65CfogcfRtnqWcqVCpHJ2U/qyc/OuNRgd2CaPbwXxkiQP4SwebWkEeCHLnn/2RZsMvmL T3Q8duW7Z0Km489YOUgEpCBmOpJfXP2zVyYgaK+bsXpA4ZN3rwqUP0eo51UBTDXe3WQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=aX23+1+G; arc=none smtp.remote-ip=95.215.58.177 Received: from mta1.migadu.com (out-177.mta1.migadu.com [95.215.58.177]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A84B9606A32E for ; Mon, 2 Nov 2026 13:01:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A84B9606A32E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=aX23+1+G X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ic6nIPaRt569Q39hvXzAm3CJLBkg+LPeh9WqbciieLg=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793624509; v=1; x=1794229309; b=aX23+1+GSfAb4heSxPGHbC4itt2et46sZoOAiZzTKmW840sXVuY9VVvs7iuP2g0p6XIr4ZtB D70KVPSkJD85JQLfPLdZcrEAm/ntdwQoCe2F1k8fZRvY0Wzus5SWWTxj6k9dgaqFT6+cqpUEkwW RNZwAVKLeVYlw7/Un/lEOopg= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id a1dd30557d3ae716; Mon, 02 Nov 2026 13:01:49 +0000 X-Mizu-Trace-ID: a1dd30557d3ae716 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton Cc: Will Deacon , Catalin Marinas , Joey Gouly , Mark Rutland , Suzuki K Poulose , Raghavendra Rao Ananta , Sascha Bischoff , Thomas Gleixner , Sebastian Ene , =?UTF-8?q?Bart=C5=82omiej=20Grzesik?= , Mostafa Saleh , Vincent Donnefort , Vladimir Murzin , Zenghui Yu , Zenghui Yu , Steffen Eiden , Radu Rendec , Fuad Tabba , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 02/13] KVM: arm64: Take host-registered MMIO regions at pKVM finalisation Date: Mon, 2 Nov 2026 13:01:22 +0000 Message-ID: <20261102130133.3684226-3-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261102130133.3684226-1-fuad.tabba@linux.dev> References: <20261102130133.3684226-1-fuad.tabba@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sebastian Ene To mediate a device, the protected KVM hypervisor has to own its registers, so that a host access to them takes a stage-2 abort rather than reaching the device. Let the host register MMIO regions before the hypervisor initialises, and have __pkvm_init_finalise() donate each one and record where it's mapped in the hypervisor's private range. The donation runs before pkvm_check_host_ownership(), which then covers those mappings too. A failed donation fails the hypervisor's initialisation before the host stage 2 is installed, so nothing is given back. Nothing registers a region yet. Signed-off-by: Sebastian Ene Co-developed-by: Fuad Tabba Signed-off-by: Fuad Tabba --- Notes: Changes since v2 (v2 patches 02 and 03, merged): - The trap handling moved to patch 9, which calls the ITS emulation directly (was a per-region callback) - Each region records its hypervisor VA - A failed donation is no longer unwound arch/arm64/include/asm/kvm_pkvm.h | 12 ++++++++++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 3 +++ arch/arm64/kvm/hyp/nvhe/setup.c | 22 ++++++++++++++++++++++ 3 files changed, 37 insertions(+) diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index fd042d2b54624..4695c35b31e1a 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -17,6 +17,18 @@ #define HYP_MEMBLOCK_REGIONS 128 +/* MMIO regions the host registers for the hypervisor to take at finalisation. */ +#define PKVM_PROTECTED_REGS_NUM 8 + +struct pkvm_protected_reg { + u64 pfn; + u64 nr_pages; + void __iomem *hyp_va; +}; + +extern struct pkvm_protected_reg kvm_nvhe_sym(pkvm_protected_regs)[]; +extern unsigned int kvm_nvhe_sym(num_protected_reg); + int pkvm_init_host_vm(struct kvm *kvm); int pkvm_create_hyp_vm(struct kvm *kvm); bool pkvm_hyp_vm_is_created(struct kvm *kvm); diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index a6dacaca77610..8d45f45d30e6a 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -28,6 +28,9 @@ struct host_mmu host_mmu; static struct hyp_pool host_s2_pool; +unsigned int num_protected_reg; +struct pkvm_protected_reg pkvm_protected_regs[PKVM_PROTECTED_REGS_NUM]; + static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm); #define current_vm (*this_cpu_ptr(&__current_vm)) diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 7bbc26b28faa5..18f348d1331a8 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -295,6 +295,24 @@ static int fix_hyp_pgtable_refcnt(void) &walker); } +static int donate_protected_mmio_regions(void) +{ + struct pkvm_protected_reg *region; + unsigned long haddr; + int ret, i; + + for (i = 0; i < num_protected_reg; i++) { + region = &pkvm_protected_regs[i]; + ret = __pkvm_host_donate_hyp_mmio(region->pfn, region->nr_pages, &haddr); + if (ret) + return ret; + + region->hyp_va = (void __iomem *)haddr; + } + + return 0; +} + void __noreturn __pkvm_init_finalise(void) { struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt); @@ -335,6 +353,10 @@ void __noreturn __pkvm_init_finalise(void) if (ret) goto out; + ret = donate_protected_mmio_regions(); + if (ret) + goto out; + ret = pkvm_check_host_ownership(); if (ret) goto out; -- 2.47.3