From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f202.google.com (mail-il1-f202.google.com [209.85.166.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85EAD28DB63 for ; Wed, 14 May 2025 19:22:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747250528; cv=none; b=qlSiBQKzcVpU0YJ8c4QIF2JzXMnUJiMMSwZBD4JVQLw9RgzdzgGcQnSLEE+yZ2OTC1RT6wvtYg+dqDLDHaZ2aYR1CQQpf8RPRUyrRNgozd85SnZPh1S2IjDtFMK3whiSa3NEjsSrUNxKSMoJr4AqyhgzcDr4VCtvUmmfy7ubx9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747250528; c=relaxed/simple; bh=6GLh2vAUb131giOvQk8M/um3okSJGroCjyJghDkewc8=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=d5w/URyGy8yfPZf7rmAtPR3fqBuOVS2KLBjyQVTLZjFAvhZARodYuhlJBRsKncwsxI+265KbVm8GeQfdjM+97Gc2wLih5Obi/Jw0HJBPI+nsRLgV0QRKNnXD7QOjTPmNeUUIKDq+WDghvWApSRWaOC8hd+pYykJeQdR7IJZ4cdM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--rananta.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=P1ZVpI1o; arc=none smtp.client-ip=209.85.166.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--rananta.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="P1ZVpI1o" Received: by mail-il1-f202.google.com with SMTP id e9e14a558f8ab-3da76423ba1so2936215ab.0 for ; Wed, 14 May 2025 12:22:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1747250525; x=1747855325; darn=lists.linux.dev; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=c8ePtC5HFZo+bckSClZmheBHRBfYWwooCNAcmQiJQhY=; b=P1ZVpI1o3jqeOsrUJ/O/yGgDsUhkRpYnBYO0QPaGqzfHZsT4yRZnVz0dDZYEYFFh94 ye6qSjIy5HqtszoAZeAbnDZYCJ6lGV2UYUdelPZ/VIxusiFvw14/IRY7HPkedU5Hc5Ss S7bnAbM6XUp3LH0QSo4AQhqhISg3edE6//Cw+dRfBHlV4ggN6ZxNV9A/lceZhtsl8daA CxJOTH0L66SUjCavcx8Ek7bKmaLAIHqA+WSqF794ml2AKY7dkNAiCZwt4govF/WAtf8a YAvQ/mV2SpOjm0PCJ2cloSqFsRQUfNEQ4n1VHxbeeUjr/SM4HLWNXxGHgOIvfk57a8hq jbVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747250525; x=1747855325; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=c8ePtC5HFZo+bckSClZmheBHRBfYWwooCNAcmQiJQhY=; b=xSlJEb4dpZK8g6NT6Krz57f+cEs6WgHVfjuGem/QwQz66qmrV5tEoalE91Kw0mB3AQ DVI6cFCAAKM0eVrjIKaD7PPANlrCkGY4zmjURTZwUjqLV0bKiJMlzorrc9BbEdDcb+8b vXexFHKDGzTfB8FyIgcgjTw7GRAJGZ32pw2H1lMf6g1j3f3D6ggt5+zbVSHndFf1H6xn msgzD+ekiUaVStZkjKAw4/Dcroj7/+6KZd/lP+Iu/NzrBDHDpxau9h95sS9kmFxhsJA+ S1kUimfw9UikLMhDd5U7cuxz4ITbooKYFlLUutvkvUT1r7f8vwXU/Ds/cLv9jvCflB7O qpOA== X-Forwarded-Encrypted: i=1; AJvYcCVd3FCyzl0xhRzJ9O+/w5XuyzjrEP8CXRwUFAM8Oe0pWEATD+6l3AW+DCezd2P8gCxsYSn65+w=@lists.linux.dev X-Gm-Message-State: AOJu0YyFDOd0OtA8qQZ8mWKhetr17g8Ip/ruF9B/koqbvyXVXozygQIe PXpOyh3aoJDk3ZiFQ37bhPODGsXfbuIS5q+ajIc21fat944OF9wK1y0qOLYbm8qAxrdXeg2znby 4IHOngw== X-Google-Smtp-Source: AGHT+IF1ogsTmn2Q4LFsh6tOmFxWnhQ3nGtiA78U3XsyCpRhWXAptzz3zxmhkhTqbmqZ1kXN3wTOk6bikL9+ X-Received: from ilbbt9.prod.google.com ([2002:a05:6e02:2489:b0:3d9:37ff:afd7]) (user=rananta job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6e02:178f:b0:3d6:cbad:235c with SMTP id e9e14a558f8ab-3db6f7ad141mr53575415ab.6.1747250525722; Wed, 14 May 2025 12:22:05 -0700 (PDT) Date: Wed, 14 May 2025 19:21:56 +0000 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.49.0.1101.gccaa498523-goog Message-ID: <20250514192159.1751538-1-rananta@google.com> Subject: [PATCH 0/3] KVM: arm64: Allow vGICv4 configuration per VM From: Raghavendra Rao Ananta To: Oliver Upton , Marc Zyngier Cc: Raghavendra Rao Anata , Mingwei Zhang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Hello, When kvm-arm.vgic_v4_enable=1, KVM adds support for direct interrupt injection by default to all the VMs in the system, aka GICv4. A shortcoming of the GIC architecture is that there's an absolute limit on the number of vPEs that can be tracked by the ITS. It is possible that an operator is running a mix of VMs on a system, only wanting to provide a specific class of VMs with hardware interrupt injection support. To support this, introduce a GIC attribute, KVM_DEV_ARM_VGIC_CONFIG_GICV4, for the userspace to enable or disable vGICv4 for a given VM. The attribute allows the configuration only when vGICv4 is enabled in KVM, else it acts a read-only attribute returning KVM_DEV_ARM_VGIC_CONFIG_GICV4_UNAVAILABLE as the value. On the other hand, if KVM has the vGICv4 enabled via the cmdline, the VM absorbs this configuration by default to maintain the backward compatibility. Userspace can get the attribute's value to check if the VM has vGICv4 support if it sees KVM_DEV_ARM_VGIC_CONFIG_GICV4_ENABLE as the value. As required, it can disable vGICv4 by setting KVM_DEV_ARM_VGIC_CONFIG_GICV4_DISABLE as the value. The patches are distrubuted as: Patch-1 contains the KVM code that introduces the KVM_DEV_ARM_VGIC_CONFIG_GICV4 attr, and adds all the support around it. Patch-2 adds the documentation for the said attribute. Patch-3 extends the vgic_init kvm/arm64 selftest that tests the get and set of this attribute in various configurations. Thank you. Raghavendra Raghavendra Rao Ananta (3): kvm: arm64: Add support for KVM_DEV_ARM_VGIC_CONFIG_GICV4 attr docs: kvm: devices/arm-vgic-v3: Document KVM_DEV_ARM_VGIC_CONFIG_GICV4 attr KVM: selftests: Extend vgic_init to test GICv4 config attr .../virt/kvm/devices/arm-vgic-v3.rst | 24 ++++++-- arch/arm64/include/uapi/asm/kvm.h | 7 +++ arch/arm64/kvm/vgic/vgic-init.c | 3 + arch/arm64/kvm/vgic/vgic-its.c | 2 +- arch/arm64/kvm/vgic/vgic-kvm-device.c | 39 +++++++++++++ arch/arm64/kvm/vgic/vgic-mmio-v3.c | 12 ++-- arch/arm64/kvm/vgic/vgic-v3.c | 16 ++++- arch/arm64/kvm/vgic/vgic-v4.c | 8 +-- include/kvm/arm_vgic.h | 5 ++ tools/testing/selftests/kvm/arm64/vgic_init.c | 58 +++++++++++++++++++ 10 files changed, 157 insertions(+), 17 deletions(-) base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 -- 2.49.0.1101.gccaa498523-goog