From patchwork Wed Jul 6 11:37:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoffer Dall X-Patchwork-Id: 9216239 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 396C160752 for ; Wed, 6 Jul 2016 11:36:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 28EE228852 for ; Wed, 6 Jul 2016 11:36:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1D42C28857; Wed, 6 Jul 2016 11:36:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2CE5928856 for ; Wed, 6 Jul 2016 11:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752183AbcGFLgv (ORCPT ); Wed, 6 Jul 2016 07:36:51 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:33544 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751201AbcGFLgh (ORCPT ); Wed, 6 Jul 2016 07:36:37 -0400 Received: by mail-wm0-f49.google.com with SMTP id r190so31862250wmr.0 for ; Wed, 06 Jul 2016 04:36:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=PMKm5f7QjDPx8h00uZ2fHNuCklmAKpc0c03UVSfwUD8=; b=DCF47H8OJiRcO3bHDLagXlr4a/gWRyZfy7B7Z6iOd0N1HfwrvFF7sw6+AYx+S5wQLP bKS/nMjJvPx93CYVxChOLsPp3nXglpy7SGGYtRpUSusevkiyPuZdmzs5V9Bgx9uQOv8k XYkUnM//XLsSwybH2uGt7JbPmTLeDyywtOx+w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=PMKm5f7QjDPx8h00uZ2fHNuCklmAKpc0c03UVSfwUD8=; b=OUfwjiuWGrwuJGBfXISZhMKgXdZ5hHFOoLDJeSHo1WIjNcv78pDpAN4ZF3Z91vYRSj vsL5sRk0CPomx/NtGEXHw9OoN86e2URuUtE8dOUqL0MpQJPfV4gPjL/6dapVQFXDryDS EBgfc8Kt1xbJdpIQO75V1tTlIKfgHqWQDiTZGq1WP28SOfXDYEslSfW8Q9HZZ+hKpOB1 P7eUCyerwiIUOCuw+Mdsq7/vIPNU55EB9loPwchRT8eBCPGff3FVbp2TNN5MyBx95Z0i hWJncjeC1cFMOl8hvI2crvtN2Ef5CUEz0+5WzCZYjtxGaQ8fgVeZT6QddZOS9nxps0hx 7kyQ== X-Gm-Message-State: ALyK8tJQFHvRxPgwrVQuFJgM2EsQG5jsTvmeEYBz32OQXGHZU4cFlS8bTvfO0RO5vkPAm5fS X-Received: by 10.28.125.71 with SMTP id y68mr21063629wmc.103.1467804986320; Wed, 06 Jul 2016 04:36:26 -0700 (PDT) Received: from localhost.localdomain ([94.18.191.146]) by smtp.gmail.com with ESMTPSA id x83sm8892640wmx.9.2016.07.06.04.36.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 06 Jul 2016 04:36:25 -0700 (PDT) From: Christoffer Dall To: kvmarm@lists.cs.columbia.edu, Peter Maydell , Marc Zyngier Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Christoffer Dall Subject: [RESEND PATCH v4] KVM: arm/arm64: Add VGICv3 save/restore API documentation Date: Wed, 6 Jul 2016 13:37:25 +0200 Message-Id: <20160706113725.32437-1-christoffer.dall@linaro.org> X-Mailer: git-send-email 2.9.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Factor out the GICv3-specific documentation into a separate documentation file. Add description for how to access distributor, redistributor, and CPU interface registers for GICv3 in this new file, and add a group for accessing level triggered IRQ information for GICv3 as well. Signed-off-by: Christoffer Dall Reviewed-by: Peter Maydell --- Changes since v3: - Fix typos - Clarified level register containing 32 IRQs - Removed limitations about priority support which are no longer true - Special-case the SPENDR register accesses to access the latch state and the CPENDR register accesses to be RAZ/WI. Changes since v2: - Changed distributor access to be 32-bits in size - Clearly specified data type pointed to by addr field - Specified exception behavior for STATUSR registers - Added group for level-triggered IRQ status info - Removed acks from Marc/Peter as content has changed Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 198 ++++++++++++++++++++++ Documentation/virtual/kvm/devices/arm-vgic.txt | 21 +-- 2 files changed, 202 insertions(+), 17 deletions(-) create mode 100644 Documentation/virtual/kvm/devices/arm-vgic-v3.txt diff --git a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt new file mode 100644 index 0000000..3eed940 --- /dev/null +++ b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt @@ -0,0 +1,198 @@ +ARM Virtual Generic Interrupt Controller v3 and later (VGICv3) +============================================================== + + +Device types supported: + KVM_DEV_TYPE_ARM_VGIC_V3 ARM Generic Interrupt Controller v3.0 + +Only one VGIC instance may be instantiated through this API. The created VGIC +will act as the VM interrupt controller, requiring emulated user-space devices +to inject interrupts to the VGIC instead of directly to CPUs. It is not +possible to create both a GICv3 and GICv2 on the same VM. + +Creating a guest GICv3 device requires a host GICv3 as well. + +Groups: + KVM_DEV_ARM_VGIC_GRP_ADDR + Attributes: + KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit) + Base address in the guest physical address space of the GICv3 distributor + register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. + This address needs to be 64K aligned and the region covers 64 KByte. + + KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit) + Base address in the guest physical address space of the GICv3 + redistributor register mappings. There are two 64K pages for each + VCPU and all of the redistributor pages are contiguous. + Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. + This address needs to be 64K aligned. + + + KVM_DEV_ARM_VGIC_GRP_DIST_REGS + KVM_DEV_ARM_VGIC_GRP_REDIST_REGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 32 | 31 .... 0 | + values: | mpidr | offset | + + All distributor regs are (rw, 32-bit) and kvm_device_attr.addr points to a + __u32 value. 64-bit registers must be accessed by separately accessing the + lower and higher word. + + Writes to read-only registers are ignored by the kernel. + + KVM_DEV_ARM_VGIC_GRP_DIST_REGS accesses the main distributor registers. + KVM_DEV_ARM_VGIC_GRP_REDIST_REGS accesses the redistributor of the CPU + specified by the mpidr. + + The offset is relative to the "[Re]Distributor base address" as defined + in the GICv3/4 specs. Getting or setting such a register has the same + effect as reading or writing the register on real hardware, except for the + following registers: GICD_STATUSR, GICR_STATUSR, GICD_ISPENDR, + GICR_ISPENDR0, GICD_ICPENDR, and GICR_ICPENDR0. These registers behave + differently when accessed via this interface compared to their + architecturally defined behavior to allow software a full view of the + VGIC's internal state. + + The mpidr field is used to specify which + redistributor is accessed. The mpidr is ignored for the distributor. + + The mpidr encoding is based on the affinity information in the + architecture defined MPIDR, and the field is encoded as follows: + | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 | + | Aff3 | Aff2 | Aff1 | Aff0 | + + Note that distributor fields are not banked, but return the same value + regardless of the mpidr used to access the register. + + The GICD_STATUSR and GICR_STATUSR registers are architecturally defined such + that a write of a clear bit has no effect, whereas a write with a set bit + clears that value. To allow userspace to freely set the values of these two + registers, setting the attributes with the register offsets for these two + registers simply sets the non-reserved bits to the value written. + + + Accesses (reads and writes) to the GICD_ISPENDR register region and + GICR_ISPENDR0 registers get/set the value of the latched pending state for + the interrupts. + + This is identical to the value read from ISPENDR for an edge triggered + interrupt, but may differ for level triggered interrupts. For edge triggered + interrupts, once an interrupt becomes pending (whether because of an edge + detected on the input line or because of a guest write to ISPENDR) this + state is "latched", and only cleared when either the interrupt is activated + or when the guest writes to ICPENDR. A level triggered interrupt may be + pending either because the level input is held high by a device, or because + of a guest write to the ISPENDR register. Only ISPENDR writes are latched; + if the device lowers the line level then the interrupt is no longer pending + unless the guest also wrote to ISPENDR, and conversely writes to ICPENDR or + activations of the interrupt do not clear the pending status if the line + level is still being held high. (These rules are documented in the GICv3 + specification descriptions of the ICPENDR and ISPENDR registers.) + For a level triggered interrupt the value accessed here + is that of the latch which is set by ISPENDR and cleared by ICPENDR or + interrupt activation, whereas the value read from ISPENDR is the logical OR + of the latch value and the input line level. + + Raw access to the latch state is provided to userspace so that it can save + and restore the entire GIC internal state (which is defined by the + combination of the current input line level and the latch state, and cannot + be deduced from purely the line level and the value of the ISPENDR + registers). + + Accesses to GICD_ICPENDR register region and GICR_ICPENDR0 registers have + RAZ/WI semantics, meaning that reads always return 0 and writes are always + ignored. + + Errors: + -ENXIO: Getting or setting this register is not yet supported + -EBUSY: One or more VCPUs are running + + + KVM_DEV_ARM_VGIC_CPU_SYSREGS + Attributes: + The attr field of kvm_device_attr encodes two values: + bits: | 63 .... 32 | 31 .... 16 | 15 .... 0 | + values: | mpidr | RES | instr | + + The mpidr field encodes the CPU ID based on the affinity information in the + architecture defined MPIDR, and the field is encoded as follows: + | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 | + | Aff3 | Aff2 | Aff1 | Aff0 | + + The instr field encodes the system register to access based on the fields + defined in the A64 instruction set encoding for system register access + (RES means the bits are reserved for future use and should be zero): + + | 15 ... 14 | 13 ... 11 | 10 ... 7 | 6 ... 3 | 2 ... 0 | + | Op 0 | Op1 | CRn | CRm | Op2 | + + All system regs accessed through this API are (rw, 64-bit) and + kvm_device_attr.addr points to a __u64 value. + + KVM_DEV_ARM_VGIC_CPU_SYSREGS accesses the CPU interface registers for the + CPU specified by the mpidr field. + + Errors: + -ENXIO: Getting or setting this register is not yet supported + -EBUSY: VCPU is running + -EINVAL: Invalid mpidr supplied + + + KVM_DEV_ARM_VGIC_GRP_NR_IRQS + Attributes: + A value describing the number of interrupts (SGI, PPI and SPI) for + this GIC instance, ranging from 64 to 1024, in increments of 32. + + kvm_device_attr.addr points to a __u32 value. + + Errors: + -EINVAL: Value set is out of the expected range + -EBUSY: Value has already be set. + + + KVM_DEV_ARM_VGIC_GRP_CTRL + Attributes: + KVM_DEV_ARM_VGIC_CTRL_INIT + request the initialization of the VGIC, no additional parameter in + kvm_device_attr.addr. + Errors: + -ENXIO: VGIC not properly configured as required prior to calling + this attribute + -ENODEV: no online VCPU + -ENOMEM: memory shortage when allocating vgic internal data + + + KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO + Attributes: + The attr field of kvm_device_attr encodes the following values: + bits: | 63 .... 32 | 31 .... 10 | 9 .... 0 | + values: | mpidr | info | vINTID | + + The vINTID specifies which set of IRQs is reported on. + + The info field specifies which information userspace wants to get or set + using this interface. Currently we support two different pieces of + information: + + VGIC_LEVEL_INFO_LINE_LEVEL: + Get/Set the input level of the IRQ line for a set of 32 contiguously + numbered interrupts. + vINTID must be a multiple of 32. + + kvm_device_attr.addr points to a __u32 value which will contain a + bitmap where a set bit means the interrupt level is asserted. + + Bit[n] indicates the status for interrupt vINTID + n. + + SGIs and any interrupt with a higher ID than the number of interrupts + supported, will be RAZ/WI. LPIs are always edge-triggered and are + therefore not supported by this interface. + + PPIs are reported per VCPU as specified in the mpidr field, and SPIs are + reported with the same value regardless of the mpidr specified. + + The mpidr field encodes the CPU ID based on the affinity information in the + architecture defined MPIDR, and the field is encoded as follows: + | 63 .... 56 | 55 .... 48 | 47 .... 40 | 39 .... 32 | + | Aff3 | Aff2 | Aff1 | Aff0 | diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index 59541d4..257b854 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -3,16 +3,16 @@ ARM Virtual Generic Interrupt Controller (VGIC) Device types supported: KVM_DEV_TYPE_ARM_VGIC_V2 ARM Generic Interrupt Controller v2.0 - KVM_DEV_TYPE_ARM_VGIC_V3 ARM Generic Interrupt Controller v3.0 Only one VGIC instance may be instantiated through either this API or the legacy KVM_CREATE_IRQCHIP api. The created VGIC will act as the VM interrupt controller, requiring emulated user-space devices to inject interrupts to the VGIC instead of directly to CPUs. -Creating a guest GICv3 device requires a host GICv3 as well. -GICv3 implementations with hardware compatibility support allow a guest GICv2 -as well. +GICv3 implementations with hardware compatibility support allow creating a +guest GICv2 through this interface. For information on creating a guest GICv3 +device, see arm-vgic-v3.txt. It is not possible to create both a GICv3 and +GICv2 device on the same VM. Groups: KVM_DEV_ARM_VGIC_GRP_ADDR @@ -27,19 +27,6 @@ Groups: interface register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V2. This address needs to be 4K aligned and the region covers 4 KByte. - KVM_VGIC_V3_ADDR_TYPE_DIST (rw, 64-bit) - Base address in the guest physical address space of the GICv3 distributor - register mappings. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. - This address needs to be 64K aligned and the region covers 64 KByte. - - KVM_VGIC_V3_ADDR_TYPE_REDIST (rw, 64-bit) - Base address in the guest physical address space of the GICv3 - redistributor register mappings. There are two 64K pages for each - VCPU and all of the redistributor pages are contiguous. - Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. - This address needs to be 64K aligned. - - KVM_DEV_ARM_VGIC_GRP_DIST_REGS Attributes: The attr field of kvm_device_attr encodes two values: