From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.206 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793883928; b=3GDjOw0e61LVqddkWEu5IbQ1VsU6lNDw9rEYLz2vDNV1ahPCf3z2so7z8pZlVozS/DPy DwzvcGKtBUpQ1xLHWVqJfXHDUhhSm+4SJLjGfdbkyhPrrHuSEo9+MyqgBRQCndiHSPGIe qIuR31nHJ8NiScxN5Z96fz1TrtFMvbESvZ5stpZpXXr0Ng7bRzaVRLFqDVHKly02p69YT EB9zgqtFH1mPqe/JdERtvUTa8yLAyRYy0vlyseaY+apI9EHezo6+gvLiElw1pqKTCdLgY vt8aVjWwxW5VypwOCHY7M1HljSOweent9uDLrLAkmkq0UPbmLy/BKxdctDH2nFw/URw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793883928; 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=U1YPN3OgBZ6MC41gzP1YSCgDTdcndw5WoSOxyRkhuTE=; b=GSuO5cUzMF1raEw1LmXtSmxKCWJCpDJMK0avLcinkLmvkSFzEf94S6ixxRvZz3FOTsTX vlPNM+sqyzRef7+ulV3t2yUiZIcImFSr0UyJv8xsZWP0fG5TFStzHodCyYvQBUeGh2p85 oX598p0AO4RpPyOMvV+egPutg31UURL/NF/d2QY6i36L5DxAn0Nj3LQ+Qm9ZkcNIFaEsc 4rYt0d4Kvn2klTH+uV5bCi7PNrB5LNdg0TxslMxLiUMNlTvO4niLbyHQxWBEClbTH4mDk JPjiRUddw9oUKTXe0tyDTqAZ8EY7sWl8FqinGeAbAy+UuuTKQL+fQ1RnQtf69NlcTZw== 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="PnjcY4h/"; arc=none smtp.remote-ip=91.218.175.206 Received: from mta0.migadu.com (out-206.mta0.migadu.com [91.218.175.206]) (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 4CF8E606A31B for ; Thu, 5 Nov 2026 13:05:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 4CF8E606A31B 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=PnjcY4h/ X-Envelope-To: kvm@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=IAD0JHK5u0AjR1SS9NS5jBII24VCj84wL7W/E6MbcFQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793883925; v=1; x=1794488725; b=PnjcY4h/pHslTwUIPa3dSfFaHqKrGwk4SQQA2UpAqzI0TAn6K2F4Gb0fxAaPcdrrxWIinxXK Qu+UuElPuNDMuBp4UeFdquyTVmoDOZ9a2jSvPjC2/+Hqv+V9tWX9/qVdjGM8fVU4iHnkItNVw1a GZWws9eoIJipNkXJDRq4f1kk= X-Envelope-To: kvm@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 981a1b1030f162c4; Thu, 05 Nov 2026 13:05:23 +0000 X-Mizu-Trace-ID: 981a1b1030f162c4 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , Catalin Marinas , Will Deacon , Mark Rutland , Vincent Donnefort , Fuad Tabba , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] KVM: arm64: Allow protected VMs to use SVE Date: Thu, 5 Nov 2026 13:04:56 +0000 Message-ID: <20261105130456.1617185-5-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261105130456.1617185-1-fuad.tabba@linux.dev> References: <20261105130456.1617185-1-fuad.tabba@linux.dev> X-Mailing-List: kvm@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 Now that EL2 owns a protected vCPU's SVE state and advertises ID_AA64ZFR0_EL1, allow KVM_CAP_ARM_SVE for a protected VM, which lets KVM_ARM_VCPU_INIT take KVM_ARM_VCPU_SVE. A protected guest's SVE access trap injects an UNDEF. An SVE instruction takes the SVE trap rather than the FP one, so a guest whose first vector instruction is an SVE one would get an UNDEF instead of the lazy FP switch. Handle the SVE trap as the FP trap is: kvm_handle_pvm_fpsimd() switches the state for a vCPU with SVE and still injects the UNDEF for one without. Update the documentation to match. Signed-off-by: Fuad Tabba --- Documentation/virt/kvm/arm/pkvm.rst | 6 +++--- arch/arm64/include/asm/kvm_pkvm.h | 1 + arch/arm64/kvm/hyp/nvhe/switch.c | 1 + arch/arm64/kvm/hyp/nvhe/sys_regs.c | 2 -- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/Documentation/virt/kvm/arm/pkvm.rst b/Documentation/virt/kvm/arm/pkvm.rst index b75bb8ad6f26d..163aa01ac5067 100644 --- a/Documentation/virt/kvm/arm/pkvm.rst +++ b/Documentation/virt/kvm/arm/pkvm.rst @@ -134,9 +134,9 @@ A protected VM boots from a single primary vCPU. Before the first * Set the primary vCPU's boot state with ``KVM_SET_ONE_REG``: the kernel entry address in ``PC`` and the DTB pointer in ``x0``. -``PC`` and ``x0`` are the only registers EL2 takes from the host. Other -pre-run writes are accepted, but the guest starts from the state the -hypervisor resets it to. +``PC``, ``x0`` and the SVE vector lengths (``KVM_REG_ARM64_SVE_VLS``) are +the only registers EL2 takes from the host. Other pre-run writes are +accepted, but the guest starts from the state the hypervisor resets it to. Secondary vCPUs are started by the guest itself through PSCI ``CPU_ON`` (see `Power state`_), which supplies their entry point and context ID. diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index fd042d2b54624..5f1b3308b42e1 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -40,6 +40,7 @@ static inline bool kvm_pkvm_ext_allowed(struct kvm *kvm, long ext) case KVM_CAP_MAX_VCPU_ID: case KVM_CAP_MSI_DEVID: case KVM_CAP_ARM_VM_IPA_SIZE: + case KVM_CAP_ARM_SVE: case KVM_CAP_ARM_PTRAUTH_ADDRESS: case KVM_CAP_ARM_PTRAUTH_GENERIC: case KVM_CAP_ONE_REG: diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 89fb9dd351ad5..0626f4203ba6d 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -230,6 +230,7 @@ static const exit_handler_fn pvm_exit_handlers[] = { [ESR_ELx_EC_WFx] = kvm_handle_pvm_wfx, [ESR_ELx_EC_HVC64] = kvm_handle_pvm_hvc64, [ESR_ELx_EC_SYS64] = kvm_handle_pvm_sys64, + [ESR_ELx_EC_SVE] = kvm_handle_pvm_fpsimd, [ESR_ELx_EC_FP_ASIMD] = kvm_handle_pvm_fpsimd, [ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low, [ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low, diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c index e6bbc897cd7b1..0ddddf957f5ab 100644 --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -502,8 +502,6 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = { ID_UNALLOCATED(7,6), ID_UNALLOCATED(7,7), - /* Scalable Vector Registers are restricted. */ - HOST_HANDLED(SYS_ICC_PMR_EL1), RAZ_WI(SYS_ERRIDR_EL1), -- 2.47.3