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2017-05-04KVM: arm/arm64: Move shared files to virt/kvm/armChristoffer Dall
For some time now we have been having a lot of shared functionality between the arm and arm64 KVM support in arch/arm, which not only required a horrible inter-arch reference from the Makefile in arch/arm64/kvm, but also created confusion for newcomers to the code base, as was recently seen on the mailing list. Further, it causes confusion for things like cscope, which needs special attention to index specific shared files for arm64 from the arm tree. Move the shared files into virt/kvm/arm and move the trace points along with it. When moving the tracepoints we have to modify the way the vgic creates definitions of the trace points, so we take the chance to include the VGIC tracepoints in its very own special vgic trace.h file. Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-02arm64: KVM: Fix decoding of Rt/Rt2 when trapping AArch32 CP accessesMarc Zyngier
Our 32bit CP14/15 handling inherited some of the ARMv7 code for handling the trapped system registers, completely missing the fact that the fields for Rt and Rt2 are now 5 bit wide, and not 4... Let's fix it, and provide an accessor for the most common Rt case. Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-20ARM: KVM: Fix idmap stub entry when running Thumb-2 codeMarc Zyngier
When entering the hyp stub implemented in the idmap, we try to be mindful of the fact that we could be running a Thumb-2 kernel by adding 1 to the address we compute. Unfortunately, the assembler also knows about this trick, and has already generated an address that has bit 0 set in the litteral pool. Our superfluous correction ends up confusing the CPU entierely, as we now branch to the stub in ARM mode instead of Thumb, and on a possibly unaligned address for good measure. From that point, nothing really good happens. The obvious fix in to remove this stupid target PC correction. Fixes: 6bebcecb6c5b ("ARM: KVM: Allow the main HYP code to use the init hyp stub implementation") Reported-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-20ARM: hyp-stub: Fix Thumb-2 compilationMarc Zyngier
The assembler defaults to emiting the short form of ADR, leading to an out-of-range immediate. Using the wide version solves this issue. Fixes: bc845e4fbbbb ("ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code") Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-19KVM: arm/arm64: vgic-v3: Fix off-by-one LR accessMarc Zyngier
When iterating over the used LRs, be careful not to try to access an unused LR, or even an unimplemented one if you're unlucky... Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-19KVM: arm/arm64: vgic-v3: De-optimize VMCR save/restore when emulating a GICv2Marc Zyngier
When emulating a GICv2-on-GICv3, special care must be taken to only save/restore VMCR_EL2 when ICC_SRE_EL1.SRE is cleared. Otherwise, all Group-0 interrupts end-up being delivered as FIQ, which is probably not what the guest expects, as demonstrated here with an unhappy EFI: FIQ Exception at 0x000000013BD21CC4 This means that we cannot perform the load/put trick when dealing with VMCR_EL2 (because the host has SRE set), and we have to deal with it in the world-switch. Fortunately, this is not the most common case (modern guests should be able to deal with GICv3 directly), and the performance is not worse than what it was before the VMCR optimization. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-19KVM: arm/arm64: fix races in kvm_psci_vcpu_onAndrew Jones
Fix potential races in kvm_psci_vcpu_on() by taking the kvm->lock mutex. In general, it's a bad idea to allow more than one PSCI_CPU_ON to process the same target VCPU at the same time. One such problem that may arise is that one PSCI_CPU_ON could be resetting the target vcpu, which fills the entire sys_regs array with a temporary value including the MPIDR register, while another looks up the VCPU based on the MPIDR value, resulting in no target VCPU found. Resolves both races found with the kvm-unit-tests/arm/psci unit test. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Reported-by: Levente Kurusa <lkurusa@redhat.com> Suggested-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Andrew Jones <drjones@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09Merge remote-tracking branch 'rutland/kvm/common-sysreg' into next-fixChristoffer Dall
2017-04-09KVM: arm/arm64: Advertise support for KVM_CAP_ARM_USER_IRQChristoffer Dall
Now that we support both timers and PMU reporting interrupts to userspace, we can advertise this support. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09KVM: arm/arm64: Report PMU overflow interrupts to userspace irqchipChristoffer Dall
When not using an in-kernel VGIC, but instead emulating an interrupt controller in userspace, we should report the PMU overflow status to that userspace interrupt controller using the KVM_CAP_ARM_USER_IRQ feature. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09KVM: arm/arm64: Support arch timers with a userspace gicAlexander Graf
If you're running with a userspace gic or other interrupt controller (that is no vgic in the kernel), then you have so far not been able to use the architected timers, because the output of the architected timers, which are driven inside the kernel, was a kernel-only construct between the arch timer code and the vgic. This patch implements the new KVM_CAP_ARM_USER_IRQ feature, where we use a side channel on the kvm_run structure, run->s.regs.device_irq_level, to always notify userspace of the timer output levels when using a userspace irqchip. This works by ensuring that before we enter the guest, if the timer output level has changed compared to what we last told userspace, we don't enter the guest, but instead return to userspace to notify it of the new level. If we are exiting, because of an MMIO for example, and the level changed at the same time, the value is also updated and userspace can sample the line as it needs. This is nicely achieved simply always updating the timer_irq_level field after the main run loop. Note that the kvm_timer_update_irq trace event is changed to show the host IRQ number for the timer instead of the guest IRQ number, because the kernel no longer know which IRQ userspace wires up the timer signal to. Also note that this patch implements all required functionality but does not yet advertise the capability. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09KVM: arm/arm64: Add ARM user space interrupt signaling ABIAlexander Graf
We have 2 modes for dealing with interrupts in the ARM world. We can either handle them all using hardware acceleration through the vgic or we can emulate a gic in user space and only drive CPU IRQ pins from there. Unfortunately, when driving IRQs from user space, we never tell user space about events from devices emulated inside the kernel, which may result in interrupt line state changes, so we lose out on for example timer and PMU events if we run with user space gic emulation. Define an ABI to publish such device output levels to userspace. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-09KVM: arm/arm64: Cleanup the arch timer code's irqchip checkingChristoffer Dall
Currently we check if we have an in-kernel irqchip and if the vgic was properly implemented several places in the arch timer code. But, we already predicate our enablement of the arm timers on having a valid and initialized gic, so we can simply check if the timers are enabled or not. This also gets rid of the ugly "error that's not an error but used to signal that the timer shouldn't poke the gic" construct we have. Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09arm/arm64: Add hyp-stub API documentationMarc Zyngier
In order to help people understanding the hyp-stub API that exists between the host kernel and the hypervisor mode (whether a hypervisor has been installed or not), let's document said API. As with any form of documentation, I expect it to become obsolete and completely misleading within 20 minutes after having being merged. Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub: Zero r0 on successful stub handlingMarc Zyngier
We now return HVC_STUB_ERR when a stub hypercall fails, but we leave whatever was in r0 on success. Zeroing it on return seems like a good idea. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Zero x0 on successful stub handlingMarc Zyngier
We now return HVC_STUB_ERR when a stub hypercall fails, but we leave whatever was in x0 on success. Zeroing it on return seems like a good idea. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub/KVM: Kill __hyp_get_vectorsMarc Zyngier
Nobody is using __hyp_get_vectors anymore, so let's remove both implementations (hyp-stub and KVM). Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub/KVM: Kill __hyp_get_vectorsMarc Zyngier
Nobody is using __hyp_get_vectors anymore, so let's remove both implementations (hyp-stub and KVM). Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: decompressor: Remove __hyp_get_vectors usageMarc Zyngier
When the compressed image needs to be relocated to avoid being overwritten by the decompression process, we need to relocate the hyp vectors as well so that we can find them once the decompression has taken effect. For that, we perform the following calculation: u32 v = __hyp_get_vectors(); v += offset; __hyp_set_vectors(v); But we're guaranteed that the initial value of v as returned by __hyp_get_vectors is always __hyp_stub_vectors, because we have just set it by calling __hyp_stub_install. So let's remove the use of __hyp_get_vectors, and directly use __hyp_stub_vectors instead. Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm/arm64: KVM: Use HVC_RESET_VECTORS to reinit HYP modeMarc Zyngier
Instead of trying to compare the value given by __hyp_get_vectors(), which doesn't offer any real guarantee to be the stub's address, use HVC_RESET_VECTORS to make sure we're in a sane state to reinstall KVM across PM events. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm/arm64: KVM: Remove kvm_get_idmap_startMarc Zyngier
With __cpu_reset_hyp_mode having become fairly dumb, there is no need for kvm_get_idmap_start anymore. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm/arm64: KVM: Use __hyp_reset_vectors() directlyMarc Zyngier
__cpu_reset_hyp_mode doesn't need to be passed any argument now, as the hyp-stub implementations are self-contained, and is now reduced to just calling __hyp_reset_vectors(). Let's drop the wrapper and use the stub hypercall directly. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Gracefully handle hyp-stubs being restored from under our feetMarc Zyngier
Should kvm_reboot() be invoked while guest is running, an IPI wil be issued, forcing the guest to exit and HYP being reset to the stubs. We will then try to reenter the guest, only to get an error (HVC_STUB_ERR). This patch allows this case to be gracefully handled by exiting the run loop. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Implement HVC_SOFT_RESTART in the init codeMarc Zyngier
Another missing stub hypercall is HVC_SOFT_RESTART. It turns out that it is pretty easy to implement in terms of HVC_RESET_VECTORS (since it needs to turn the MMU off). Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectorsMarc Zyngier
We are now able to use the hyp stub to reset HYP mode. Time to kiss __kvm_hyp_reset goodbye, and use __hyp_reset_vectors. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Allow the main HYP code to use the init hyp stub implementationMarc Zyngier
We now have a full hyp-stub implementation in the KVM init code, but the main KVM code only supports HVC_GET_VECTORS, which is not enough. Instead of reinventing the wheel, let's reuse the init implementation by branching to the idmap page when called with a hyp-stub hypercall. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Implement HVC_GET_VECTORS in the init codeMarc Zyngier
Now that we have an infrastructure to handle hypercalls in the KVM init code, let's implement HVC_GET_VECTORS there. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init codeMarc Zyngier
In order to restore HYP mode to its original condition, KVM currently implements __kvm_hyp_reset(). As we're moving towards a hyp-stub defined API, it becomes necessary to implement HVC_RESET_VECTORS. This patch adds the HVC_RESET_VECTORS hypercall to the KVM init code, which so far lacked any form of hypercall support. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub: Implement HVC_RESET_VECTORS stub hypercallMarc Zyngier
Let's define a new stub hypercall that resets the HYP configuration to its default: hyp-stub vectors, and MMU disabled. Of course, for the hyp-stub itself, this is a trivial no-op. Hypervisors will have a bit more work to do. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub: Define a return value for failed stub callsMarc Zyngier
Define a standard return value to be returned when a hyp stub call fails. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: Expose the VA/IDMAP offsetMarc Zyngier
The KVM code needs to be able to compute the address of symbols in its idmap page (the equivalent of a virt_to_idmap() call). Unfortunately, virt_to_idmap is slightly complicated, depending on the use of arch_phys_to_idmap_offset or not, and none of that is readily available at HYP. Instead, expose a single kimage_voffset variable which contains the offset between a kernel VA and its idmap address, enabling the VA->IDMAP conversion. This allows the KVM code to behave similarily to its arm64 counterpart. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub: Use r1 for the soft-restart addressMarc Zyngier
It is not really obvious why the restart address should be in r3 when communicated to the hyp-stub. r1 should be perfectly adequate, and consistent with the rest of the code. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: Update cpu_v7_reset documentationMarc Zyngier
cpu_v7_reset() now takes a second parameter indicating whether we should reboot in HYP or not. Update the documentation to reflect this. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: KVM: Convert KVM to use HVC_GET_VECTORSMarc Zyngier
The conversion of the HYP stub ABI to something similar to arm64 left the KVM code broken, as it doesn't know about the new stub numbering. Let's move the various #defines to virt.h, and let KVM use HVC_GET_VECTORS. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: soft-reboot into same mode that we entered the kernelRussell King
When we soft-reboot (eg, kexec) from one kernel into the next, we need to ensure that we enter the new kernel in the same processor mode as when we were entered, so that (eg) the new kernel can install its own hypervisor - the old kernel's hypervisor will have been overwritten. In order to do this, we need to pass a flag to cpu_reset() so it knows what to do, and we need to modify the kernel's own hypervisor stub to allow it to handle a soft-reboot. As we are always guaranteed to install our own hypervisor if we're entered in HYP32 mode, and KVM will have moved itself out of the way on kexec/normal reboot, we can assume that our hypervisor is in place when we want to kexec, so changing our hypervisor API should not be a problem. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09ARM: hyp-stub: improve ABIRussell King
Improve the hyp-stub ABI to allow it to do more than just get/set the vectors. We follow the example in ARM64, where r0 is used as an opcode with the other registers as an argument. Tested-by: Keerthy <j-keerthy@ti.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Implement HVC_SOFT_RESTART in the init codeMarc Zyngier
Another missing stub hypercall is HVC_SOFT_RESTART. It turns out that it is pretty easy to implement in terms of HVC_RESET_VECTORS (since it needs to turn the MMU off). Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectorsMarc Zyngier
We are now able to use the hyp stub to reset HYP mode. Time to kiss __kvm_hyp_reset goodbye, and use __hyp_reset_vectors. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Allow the main HYP code to use the init hyp stub implementationMarc Zyngier
We now have a full hyp-stub implementation in the KVM init code, but the main KVM code only supports HVC_GET_VECTORS, which is not enough. Instead of reinventing the wheel, let's reuse the init implementation by branching to the idmap page when called with a hyp-stub hypercall. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Implement HVC_GET_VECTORS in the init codeMarc Zyngier
Now that we have an infrastructure to handle hypercalls in the KVM init code, let's implement HVC_GET_VECTORS there. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init codeMarc Zyngier
In order to restore HYP mode to its original condition, KVM currently implements __kvm_hyp_reset(). As we're moving towards a hyp-stub defined API, it becomes necessary to implement HVC_RESET_VECTORS. This patch adds the HVC_RESET_VECTORS hypercall to the KVM init code, which so far lacked any form of hypercall support. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Implement HVC_RESET_VECTORS stub hypercallMarc Zyngier
Let's define a new stub hypercall that resets the HYP configuration to its default: hyp-stub vectors, and MMU disabled. Of course, for the hyp-stub itself, this is a trivial no-op. Hypervisors will have a bit more work to do. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Update documentation in asm/virt.hMarc Zyngier
Comments in asm/virt.h are slightly out of date, so let's align them with the new behaviour of the code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Define a return value for failed stub callsMarc Zyngier
Define a standard return value to be returned when a hyp stub call fails, and make KVM use it for ARM_EXCEPTION_HYP_GONE (instead of using a KVM-specific value). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Don't save lr in the EL1 codeMarc Zyngier
The EL2 code is not corrupting lr anymore, so don't bother preserving it in the EL1 trampoline code. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: KVM: Move lr save/restore to do_el2_callMarc Zyngier
At the moment, we only save/restore lr if on VHE, as we rely only the EL1 code to have preserved it in the non-VHE case. As we're about to get rid of the latter, let's move the save/restore code to the do_el2_call macro, unifying both code paths. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm64: hyp-stub: Stop pointlessly clobbering lrMarc Zyngier
When entering the kernel hyp stub, we check whether or not we've made it here through an HVC instruction, clobbering lr (aka x30) in the process. This is completely pointless, as HVC is the only way to get here (all traps to EL2 are disabled, no interrupt override is applied). So let's remove this bit of code whose only point is to corrupt a valuable register. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09arm: KVM: Treat CP15 accessors returning false as successfulMarc Zyngier
Instead of considering that a CP15 accessor has failed when returning false, let's consider that it is *always* successful (after all, we won't stand for an incomplete emulation). The return value now simply indicates whether we should skip the instruction (because it has now been emulated), or if we should leave the PC alone if the emulation has injected an exception. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-09arm: KVM: Make unexpected register accesses inject an undefMarc Zyngier
Reads from write-only system registers are generally confined to EL1 and not propagated to EL2 (that's what the architecture mantates). In order to be sure that we have a sane behaviour even in the unlikely event that we have a broken system, we still handle it in KVM. Same goes for write to RO registers. In that case, let's inject an undef into the guest. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-09arm64: KVM: Do not corrupt registers on failed 64bit CP readMarc Zyngier
If we fail to emulate a mrrc instruction, we: 1) deliver an exception, 2) spit a nastygram on the console, 3) write back some garbage to Rt/Rt2 While 1) and 2) are perfectly acceptable, 3) is out of the scope of the architecture... Let's mimick the code in kvm_handle_cp_32 and be more cautious. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>