summaryrefslogtreecommitdiffstats
path: root/virt/kvm/arm/vgic/vgic.c
Commit message (Collapse)AuthorAgeFilesLines
...
| * KVM: arm/arm64: vgic: Get rid of unnecessary process_maintenance operationChristoffer Dall2017-04-091-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we always read back the LRs that we wrote to the guest and the MISR and EISR registers simply provide a summary of the configuration of the bits in the LRs, there is really no need to read back those status registers and process them. We might as well just signal the notifyfd when folding the LR state and save some cycles in the process. We now clear the underflow bit in the fold_lr_state functions as we only need to clear this bit if we had used all the LRs, so this is as good a place as any to do that work. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| * KVM: arm/arm64: vgic: Only set underflow when actually out of LRsChristoffer Dall2017-04-091-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently assume that all the interrupts in our AP list will be queued to LRs, but that's not necessarily the case, because some of them could have been migrated away to different VCPUs and only the VCPU thread itself can remove interrupts from its AP list. Therefore, slightly change the logic to only setting the underflow interrupt when we actually run out of LRs. As it turns out, this allows us to further simplify the handling in vgic_sync_hwstate in later patches. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
| * KVM: arm/arm64: vgic: Avoid flushing vgic state when there's no pending IRQShih-Wei Li2017-04-091-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We do not need to flush vgic states in each world switch unless there is pending IRQ queued to the vgic's ap list. We can thus reduce the overhead by not grabbing the spinlock and not making the extra function call to vgic_flush_lr_state. Note: list_empty is a single atomic read (uses READ_ONCE) and can therefore check if a list is empty or not without the need to take the spinlock protecting the list. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
| * KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/putChristoffer Dall2017-04-091-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't have to save/restore the VMCR on every entry to/from the guest, since on GICv2 we can access the control interface from EL1 and on VHE systems with GICv3 we can access the control interface from KVM running in EL2. GICv3 systems without VHE becomes the rare case, which has to save/restore the register on each round trip. Note that userspace accesses may see out-of-date values if the VCPU is running while accessing the VGIC state via the KVM device API, but this is already the case and it is up to userspace to quiesce the CPUs before reading the CPU registers from the GIC for an up-to-date view. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
* | arm: kvm: move kvm_vgic_global_state out of .text sectionArd Biesheuvel2017-03-231-1/+3
|/ | | | | | | | | | | | | | | The kvm_vgic_global_state struct contains a static key which is written to by jump_label_init() at boot time. So in preparation of making .text regions truly (well, almost truly) read-only, mark kvm_vgic_global_state __ro_after_init so it moves to the .rodata section instead. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* KVM: arm/arm64: Remove kvm_vgic_inject_mapped_irqChristoffer Dall2017-02-011-34/+16
| | | | | | | | | | | | | | | The only benefit of having kvm_vgic_inject_mapped_irq separate from kvm_vgic_inject_irq is that we pass a boolean that we use for error checking on the injection path. While this could potentially help in some aspect of robustness, it's also a little bit of a defensive move, and arguably callers into the vgic should have make sure they have marked their virtual IRQs as mapped if required. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: Remove struct vgic_irq pending fieldChristoffer Dall2017-01-251-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the goals behind the VGIC redesign was to get rid of cached or intermediate state in the data structures, but we decided to allow ourselves to precompute the pending value of an IRQ based on the line level and pending latch state. However, this has now become difficult to base proper GICv3 save/restore on, because there is a potential to modify the pending state without knowing if an interrupt is edge or level configured. See the following post and related message for more background: https://lists.cs.columbia.edu/pipermail/kvmarm/2017-January/023195.html This commit gets rid of the precomputed pending field in favor of a function that calculates the value when needed, irq_is_pending(). The soft_pending field is renamed to pending_latch to represent that this latch is the equivalent hardware latch which gets manipulated by the input signal for edge-triggered interrupts and when writing to the SPENDR/CPENDR registers. After this commit save/restore code should be able to simply restore the pending_latch state, line_level state, and config state in any order and get the desired result. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic: Kick VCPUs when queueing already pending IRQsShih-Wei Li2016-11-041-0/+12
| | | | | | | | | | | | | | In cases like IPI, we could be queueing an interrupt for a VCPU that is already running and is not about to exit, because the VCPU has entered the VM with the interrupt pending and would not trap on EOI'ing that interrupt. This could result to delays in interrupt deliveries or even loss of interrupts. To guarantee prompt interrupt injection, here we have to try to kick the VCPU. Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm/arm64: vgic: Don't flush/sync without a working vgicChristoffer Dall2016-09-271-0/+6
| | | | | | | | | | | | | | If the vgic hasn't been created and initialized, we shouldn't attempt to look at its data structures or flush/sync anything to the GIC hardware. This fixes an issue reported by Alexander Graf when using a userspace irqchip. Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework") Cc: stable@vger.kernel.org Reported-by: Alexander Graf <agraf@suse.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* arm64: KVM: Use static keys for selecting the GIC backendVladimir Murzin2016-09-221-1/+1
| | | | | | | | | | | | | | | | | | | Currently GIC backend is selected via alternative framework and this is fine. We are going to introduce vgic-v3 to 32-bit world and there we don't have patching framework in hand, so we can either check support for GICv3 every time we need to choose which backend to use or try to optimise it by using static keys. The later looks quite promising because we can share logic involved in selecting GIC backend between architectures if both uses static keys. This patch moves arm64 from alternative to static keys framework for selecting GIC backend. For that we embed static key into vgic_global and enable the key during vgic initialisation based on what has already been exposed by the host GIC driver. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm64: vgic-its: Plug race in vgic_put_irqChristoffer Dall2016-08-101-5/+5
| | | | | | | | | | | | | | | | | Right now the following sequence of events can happen: 1. Thread X calls vgic_put_irq 2. Thread Y calls vgic_add_lpi 3. Thread Y gets lpi_list_lock 4. Thread X drops the ref count to 0 and blocks on lpi_list_lock 5. Thread Y finds the irq via the lpi_list_lock, raises the ref count to 1, and release the lpi_list_lock. 6. Thread X proceeds and frees the irq. Avoid this by holding the spinlock around the kref_put. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: Enable irqchip routingEric Auger2016-07-221-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds compilation and link against irqchip. Main motivation behind using irqchip code is to enable MSI routing code. In the future irqchip routing may also be useful when targeting multiple irqchips. Routing standard callbacks now are implemented in vgic-irqfd: - kvm_set_routing_entry - kvm_set_irq - kvm_set_msi They only are supported with new_vgic code. Both HAVE_KVM_IRQCHIP and HAVE_KVM_IRQ_ROUTING are defined. KVM_CAP_IRQ_ROUTING is advertised and KVM_SET_GSI_ROUTING is allowed. So from now on IRQCHIP routing is enabled and a routing table entry must exist for irqfd injection to succeed for a given SPI. This patch builds a default flat irqchip routing table (gsi=irqchip.pin) covering all the VGIC SPI indexes. This routing table is overwritten by the first first user-space call to KVM_SET_GSI_ROUTING ioctl. MSI routing setup is not yet allowed. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm64: vgic-its: Generalize use of vgic_get_irq_krefMarc Zyngier2016-07-181-9/+1
| | | | | | | | | | 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>
* KVM: arm64: vgic-its: Enable ITS emulation as a virtual MSI controllerAndre Przywara2016-07-181-0/+8
| | | | | | | | | | | Now that all ITS emulation functionality is in place, we advertise MSI functionality to userland and also the ITS device to the guest - if userland has configured 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>
* KVM: arm64: vgic-its: Connect LPIs to the VGIC emulationAndre Przywara2016-07-181-6/+57
| | | | | | | | | | | | | | | | | | | 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>
* KVM: arm64: vgic-its: Implement basic ITS register handlersAndre Przywara2016-07-181-3/+9
| | | | | | | | | | | | | | | | | | | | | 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>
* KVM: arm/arm64: vgic: Add refcounting for IRQsAndre Przywara2016-07-181-4/+48
| | | | | | | | | | | | | | | | | | | | In the moment our struct vgic_irq's are statically allocated at guest creation time. So getting a pointer to an IRQ structure is trivial and safe. LPIs are more dynamic, they can be mapped and unmapped at any time during the guest's _runtime_. In preparation for supporting LPIs we introduce reference counting for those structures using the kernel's kref infrastructure. Since private IRQs and SPIs are statically allocated, we avoid actually refcounting them, since they would never be released anyway. But we take provisions to increase the refcount when an IRQ gets onto a VCPU list and decrease it when it gets removed. Also this introduces vgic_put_irq(), which wraps kref_put and hides the release function from the callers. 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>
* KVM: arm/arm64: vgic-new: implement mapped IRQ handlingAndre Przywara2016-05-201-0/+53
| | | | | | | | | | We now store the mapped hardware IRQ number in our struct, so we don't need the irq_phys_map for the new VGIC. Implement the hardware IRQ mapping on top of the reworked arch timer interface. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: vgic_init: implement vgic_initEric Auger2016-05-201-0/+4
| | | | | | | | | | This patch allocates and initializes the data structures used to model the vgic distributor and virtual cpu interfaces. At that stage the number of IRQs and number of virtual CPUs is frozen. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlersMarc Zyngier2016-05-201-0/+15
| | | | | | | | | | | | Those three registers are v2 emulation specific, so their implementation lives entirely in vgic-mmio-v2.c. Also they are handled in one function, as their implementation is pretty simple. When the guest enables the distributor, we kick all VCPUs to get potentially pending interrupts serviced. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irqEric Auger2016-05-201-0/+25
| | | | | | | | | | Tell KVM whether a particular VCPU has an IRQ that needs handling in the guest. This is used to decide whether a VCPU is runnable. Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm/arm64: vgic-new: Add GICv3 world switch backendMarc Zyngier2016-05-201-5/+20
| | | | | | | | | | | | As the GICv3 virtual interface registers differ from their GICv2 siblings, we need different handlers for processing maintenance interrupts and reading/writing to the LRs. Implement the respective handler functions and connect them to existing code to be called if the host is using a GICv3. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: Add GICv2 world switch backendMarc Zyngier2016-05-201-0/+6
| | | | | | | | | | | | | | | Processing maintenance interrupts and accessing the list registers are dependent on the host's GIC version. Introduce vgic-v2.c to contain GICv2 specific functions. Implement the GICv2 specific code for syncing the emulation state into the VGIC registers. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: Add IRQ sync/flush frameworkMarc Zyngier2016-05-201-0/+192
| | | | | | | | | | | | | | | | Implement the framework for syncing IRQs between our emulation and the list registers, which represent the guest's view of IRQs. This is done in kvm_vgic_flush_hwstate and kvm_vgic_sync_hwstate, which gets called on guest entry and exit. The code talking to the actual GICv2/v3 hardware is added in the following patches. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Eric Auger <eric.auger@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
* KVM: arm/arm64: vgic-new: Add IRQ sortingChristoffer Dall2016-05-201-0/+57
| | | | | | | | | | Adds the sorting function to cover the case where you have more IRQs to consider than you have LRs. We now consider priorities. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: arm/arm64: vgic-new: Implement virtual IRQ injectionChristoffer Dall2016-05-201-0/+211
| | | | | | | | | | | | | | | | | Provide a vgic_queue_irq_unlock() function which decides whether a given IRQ needs to be queued to a VCPU's ap_list. This should be called whenever an IRQ becomes pending or enabled, either as a result of userspace injection, from in-kernel emulated devices like the architected timer or from MMIO accesses to the distributor emulation. Also provides the necessary functions to allow userland to inject an IRQ to a guest. Since this is the first code that starts using our locking mechanism, we add some (hopefully) clear documentation of our locking strategy and requirements along with this patch. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
* KVM: arm/arm64: vgic-new: Add acccessor to new struct vgic_irq instanceChristoffer Dall2016-05-201-0/+41
The new VGIC implementation centers around a struct vgic_irq instance per virtual IRQ. Provide a function to retrieve the right instance for a given IRQ number and (in case of private interrupts) the right VCPU. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
OpenPOWER on IntegriCloud