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path: root/virt/kvm/arm/vgic/vgic-its.c
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2016-08-16KVM: arm64: ITS: avoid re-mapping LPIsAndre Przywara
When a guest wants to map a device-ID/event-ID combination that is already mapped, we may end up in a situation where an LPI is never "put", thus never being freed. Since the GICv3 spec says that mapping an already mapped LPI is UNPREDICTABLE, lets just bail out early in this situation to avoid any potential leaks. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15KVM: arm64: check for ITS device on MSI injectionAndre Przywara
When userspace provides the doorbell address for an MSI to be injected into the guest, we find a KVM device which feels responsible. Lets check that this device is really an emulated ITS before we make real use of the container_of-ed pointer. [ Moved NULL-pointer check to caller of static function - Christoffer ] Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15KVM: arm64: ITS: move ITS registration into first VCPU runAndre Przywara
Currently we register an ITS device upon userland issuing the CTLR_INIT ioctl to mark initialization of the ITS as done. This deviates from the initialization sequence of the existing GIC devices and does not play well with the way QEMU handles things. To be more in line with what we are used to, register the ITS(es) just before the first VCPU is about to run, so in the map_resources() call. This involves iterating through the list of KVM devices and map each ITS that we find. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-10KVM: arm64: vgic-its: Handle errors from vgic_add_lpiChristoffer Dall
During low memory conditions, we could be dereferencing a NULL pointer when vgic_add_lpi fails to allocate memory. Consider for example this call sequence: vgic_its_cmd_handle_mapi itte->irq = vgic_add_lpi(kvm, lpi_nr); update_lpi_config(kvm, itte->irq, NULL); ret = kvm_read_guest(kvm, propbase + irq->intid ^^^^ kaboom? Instead, return an error pointer from vgic_add_lpi and check the return value from its single caller. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-09KVM: arm64: ITS: return 1 on successful MSI injectionAndre Przywara
According to the KVM API documentation a successful MSI injection should return a value > 0 on success. Return possible errors in vgic_its_trigger_msi() and report a successful injection back to userland, while also reporting the case where the MSI could not be delivered due to the guest not having the LPI mapped, for instance. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-18KVM: arm64: vgic-its: Simplify MAPI error handlingMarc Zyngier
If we care to move all the checks that do not involve any memory allocation, we can simplify the MAPI error handling. Let's do that, it cannot hurt. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlersMarc Zyngier
vgic_its_cmd_handle_mapi has an extra "subcmd" argument, which is already contained in the command buffer that all command handlers obtain from the command queue. Let's drop it, as it is not that useful. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Turn device_id validation into generic ID validationMarc Zyngier
There is no need to have separate functions to validate devices and collections, as the architecture doesn't really distinguish the two, and they are supposed to be managed the same way. Let's turn the DevID checker into a generic one. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Add pointer to corresponding kvm_deviceMarc Zyngier
Going from the ITS structure to the corresponding KVM structure would be quite handy at times. The kvm_device pointer that is passed at create time is quite convenient for this, so let's keep a copy of it in the vgic_its structure. This will be put to a good use in subsequent patches. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Add collection allocator/destructorMarc Zyngier
Instead of spreading random allocations all over the place, consolidate allocation/init/freeing of collections in a pair of constructor/destructor. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Fix L2 entry validation for indirect tablesMarc Zyngier
When checking that the storage address of a device entry is valid, it is critical to compute the actual address of the entry, rather than relying on the beginning of the page to match a CPU page of the same size: for example, if the guest places the table at the last 64kB boundary of RAM, but RAM size isn't a multiple of 64kB... Fix this by computing the actual offset of the device ID in the L2 page, and check the corresponding GFN. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Validate the device table L1 entryMarc Zyngier
Checking that the device_id fits if the table, and we must make sure that the associated memory is also accessible. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Fix misleading nr_entries in vgic_its_check_device_idMarc Zyngier
The nr_entries variable in vgic_its_check_device_id actually describe the size of the L1 table, and not the number of entries in this table. Rename it to l1_tbl_size, so that we can now change the code with a better understanding of what is what. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Fix vgic_its_check_device_id BE handlingMarc Zyngier
The ITS tables are stored in LE format. If the host is reading a L1 table entry to check its validity, it must convert it to the CPU endianness. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Fix handling of indirect tablesMarc Zyngier
The current code will fail on valid indirect tables, and happily use the ones that are pointing out of the guest RAM. Funny what a small "!" can do for you... Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Generalize use of vgic_get_irq_krefMarc Zyngier
Instead of sprinkling raw kref_get() calls everytime we cannot do a normal vgic_get_irq(), use the existing vgic_get_irq_kref(), which does the same thing and is paired with a vgic_put_irq(). vgic_get_irq_kref is moved to vgic.h in order to be easily shared. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Implement MSI injection in ITS emulationAndre Przywara
When userland wants to inject an MSI into the guest, it uses the KVM_SIGNAL_MSI ioctl, which carries the doorbell address along with the payload and the device ID. With the help of the KVM IO bus framework we learn the corresponding ITS from the doorbell address. We then use our wrapper functions to iterate the linked lists and find the proper Interrupt Translation Table Entry (ITTE) and thus the corresponding struct vgic_irq to finally set the pending bit. We also provide the handler for the ITS "INT" command, which allows a guest to trigger an MSI via the ITS command queue. Since this one knows about the right ITS already, we directly call the MMIO handler function without using the kvm_io_bus framework. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Implement ITS command queue command handlersAndre Przywara
The connection between a device, an event ID, the LPI number and the associated CPU is stored in in-memory tables in a GICv3, but their format is not specified by the spec. Instead software uses a command queue in a ring buffer to let an ITS implementation use its own format. Implement handlers for the various ITS commands and let them store the requested relation into our own data structures. Those data structures are protected by the its_lock mutex. Our internal ring buffer read and write pointers are protected by the its_cmd mutex, so that only one VCPU per ITS can handle commands at any given time. Error handling is very basic at the moment, as we don't have a good way of communicating errors to the guest (usually an SError). The INT command handler is missing from this patch, as we gain the capability of actually injecting MSIs into the guest only later on. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Allow updates of LPI configuration tableAndre Przywara
The (system-wide) LPI configuration table is held in a table in (guest) memory. To achieve reasonable performance, we cache this data in our struct vgic_irq. If the guest updates the configuration data (which consists of the enable bit and the priority value), it issues an INV or INVALL command to allow us to update our information. Provide functions that update that information for one LPI or all LPIs mapped to a specific collection. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Read initial LPI pending tableAndre Przywara
The LPI pending status for a GICv3 redistributor is held in a table in (guest) memory. To achieve reasonable performance, we cache the pending bit in our struct vgic_irq. The initial pending state must be read from guest memory upon enabling LPIs for this redistributor. As we can't access the guest memory while we hold the lpi_list spinlock, we create a snapshot of the LPI list and iterate over that. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Connect LPIs to the VGIC emulationAndre Przywara
LPIs are dynamically created (mapped) at guest runtime and their actual number can be quite high, but is mostly assigned using a very sparse allocation scheme. So arrays are not an ideal data structure to hold the information. We use a spin-lock protected linked list to hold all mapped LPIs, represented by their struct vgic_irq. This lock is grouped between the ap_list_lock and the vgic_irq lock in our locking order. Also we store a pointer to that struct vgic_irq in our struct its_itte, so we can easily access it. Eventually we call our new vgic_get_lpi() from vgic_get_irq(), so the VGIC code gets transparently access to LPIs. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Implement basic ITS register handlersAndre Przywara
Add emulation for some basic MMIO registers used in the ITS emulation. This includes: - GITS_{CTLR,TYPER,IIDR} - ID registers - GITS_{CBASER,CREADR,CWRITER} (which implement the ITS command buffer handling) - GITS_BASER<n> Most of the handlers are pretty straight forward, only the CWRITER handler is a bit more involved by taking the new its_cmd mutex and then iterating over the command buffer. The registers holding base addresses and attributes are sanitised before storing them. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Introduce new KVM ITS deviceAndre Przywara
Introduce a new KVM device that represents an ARM Interrupt Translation Service (ITS) controller. Since there can be multiple of this per guest, we can't piggy back on the existing GICv3 distributor device, but create a new type of KVM device. On the KVM_CREATE_DEVICE ioctl we allocate and initialize the ITS data structure and store the pointer in the kvm_device data. Upon an explicit init ioctl from userland (after having setup the MMIO address) we register the handlers with the kvm_io_bus framework. Any reference to an ITS thus has to go via this interface. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Introduce ITS emulation file with MMIO frameworkAndre Przywara
The ARM GICv3 ITS emulation code goes into a separate file, but needs to be connected to the GICv3 emulation, of which it is an option. The ITS MMIO handlers require the respective ITS pointer to be passed in, so we amend the existing VGIC MMIO framework to let it cope with that. Also we introduce the basic ITS data structure and initialize it, but don't return any success yet, as we are not yet ready for the show. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>