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2017-08-08KVM: arm: implements the kvm_arch_vcpu_in_kernel()Longpeng(Mike)
This implements the kvm_arch_vcpu_in_kernel() for ARM, and adjusts the calls to kvm_vcpu_on_spin(). Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-08-08KVM: add spinlock optimization frameworkLongpeng(Mike)
If a vcpu exits due to request a user mode spinlock, then the spinlock-holder may be preempted in user mode or kernel mode. (Note that not all architectures trap spin loops in user mode, only AMD x86 and ARM/ARM64 currently do). But if a vcpu exits in kernel mode, then the holder must be preempted in kernel mode, so we should choose a vcpu in kernel mode as a more likely candidate for the lock holder. This introduces kvm_arch_vcpu_in_kernel() to decide whether the vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's new argument says the same of the spinning VCPU. Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15Merge branch 'kvmarm-master/master' into HEADMarc Zyngier
2017-06-08KVM: arm/arm64: Allow setting the timer IRQ numbers from userspaceChristoffer Dall
First we define an ABI using the vcpu devices that lets userspace set the interrupt numbers for the various timers on both the 32-bit and 64-bit KVM/ARM implementations. Second, we add the definitions for the groups and attributes introduced by the above ABI. (We add the PMU define on the 32-bit side as well for symmetry and it may get used some day.) Third, we set up the arch-specific vcpu device operation handlers to call into the timer code for anything related to the KVM_ARM_VCPU_TIMER_CTRL group. Fourth, we implement support for getting and setting the timer interrupt numbers using the above defined ABI in the arch timer code. Fifth, we introduce error checking upon enabling the arch timer (which is called when first running a VCPU) to check that all VCPUs are configured to use the same PPI for the timer (as mandated by the architecture) and that the virtual and physical timers are not configured to use the same IRQ number. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Move timer IRQ default init to arch_timer.cChristoffer Dall
We currently initialize the arch timer IRQ numbers from the reset code, presumably because we once intended to model multiple CPU or SoC types from within the kernel and have hard-coded reset values in the reset code. As we are moving towards userspace being in charge of more fine-grained CPU emulation and stitching together the pieces needed to emulate a particular type of CPU, we should no longer have a tight coupling between resetting a VCPU and setting IRQ numbers. Therefore, move the logic to define and use the default IRQ numbers to the timer code and set the IRQ number immediately when creating the VCPU. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm: Handle VCPU device attributes in guest.cChristoffer Dall
As we are about to support VCPU attributes to set the timer IRQ numbers in guest.c, move the static inlines for the VCPU attributes handlers from the header file to guest.c. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-06arm: KVM: Allow unaligned accesses at HYPMarc Zyngier
We currently have the HSCTLR.A bit set, trapping unaligned accesses at HYP, but we're not really prepared to deal with it. Since the rest of the kernel is pretty happy about that, let's follow its example and set HSCTLR.A to zero. Modern CPUs don't really care. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-04KVM: arm/arm64: properly use vcpu requestsAndrew Jones
arm/arm64 already has one VCPU request used when setting pause, but it doesn't properly check requests in VCPU RUN. Check it and also make sure we set vcpu->mode at the appropriate time (before the check) and with the appropriate barriers. See Documentation/virtual/kvm/vcpu-requests.rst. Also make sure we don't leave any vcpu requests we don't intend to handle later set in the request bitmap. If we don't clear them, then kvm_request_pending() may return true when it shouldn't. Using VCPU requests properly fixes a small race where pause could get set just as a VCPU was entering guest mode. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-16KVM: arm: Restore banked registers and physical timer access on hyp_panic()James Morse
When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too. At some point panic() touches the physical timer/counter, this will trap back to HYP. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15KVM: arm: rename pm_fake handler to trap_raz_wiZhichao Huang
pm_fake doesn't quite describe what the handler does (ignoring writes and returning 0 for reads). As we're about to use it (a lot) in a different context, rename it with a (admitedly cryptic) name that make sense for all users. Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org> Reviewed-by: Alex Bennee <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15KVM: arm: plug potential guest hardware debug leakageZhichao Huang
Hardware debugging in guests is not intercepted currently, it means that a malicious guest can bring down the entire machine by writing to the debug registers. This patch enable trapping of all debug registers, preventing the guests to access the debug registers. This includes access to the debug mode(DBGDSCR) in the guest world all the time which could otherwise mess with the host state. Reads return 0 and writes are ignored (RAZ_WI). The result is the guest cannot detect any working hardware based debug support. As debug exceptions are still routed to the guest normal debug using software based breakpoints still works. To support debugging using hardware registers we need to implement a debug register aware world switch as well as special trapping for registers that may affect the host state. Cc: stable@vger.kernel.org Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15arm: KVM: Do not use stack-protector to compile HYP codeMarc Zyngier
We like living dangerously. Nothing explicitely forbids stack-protector to be used in the HYP code, while distributions routinely compile their kernel with it. We're just lucky that no code actually triggers the instrumentation. Let's not try our luck for much longer, and disable stack-protector for code living at HYP. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15ARM: KVM: Fix tracepoint generation after move to virt/kvm/arm/Marc Zyngier
Moving most of the shared code to virt/kvm/arm had for consequence that KVM/ARM doesn't build anymore, because the code that used to define the tracepoints is now somewhere else. Fix this by defining CREATE_TRACE_POINTS in coproc.c, and clean-up trace.h as well. Fixes: 35d2d5d490e2 ("KVM: arm/arm64: Move shared files to virt/kvm/arm") Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-04KVM: 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>
2017-04-20ARM: 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>
2017-04-19KVM: 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>
2017-04-09KVM: 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>
2017-04-09ARM: 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>
2017-04-09ARM: 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/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: 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: 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>
2017-04-09KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/putChristoffer Dall
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>
2017-04-09kvm: arm/arm64: Rework gpa callback handlersSuzuki K Poulose
In order to perform an operation on a gpa range, we currently iterate over each page in a user memory slot for the given range. This is inefficient while dealing with a big range (e.g, a VMA), especially while unmaping a range. At present, with stage2 unmap on a range with a hugepage backed region, we clear the PMD when we unmap the first page in the loop. The remaining iterations simply traverse the page table down to the PMD level only to see that nothing is in there. This patch reworks the code to invoke the callback handlers on the biggest range possible within the memory slot to to reduce the number of times the handler is called. Cc: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-03-09KVM: arm/arm64: Enable KVM_CAP_NR_MEMSLOTS on arm/arm64Linu Cherian
Return KVM_USER_MEM_SLOTS for userspace capability query on NR_MEMSLOTS. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Linu Cherian <linu.cherian@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-07arm: KVM: Survive unknown traps from guestsMark Rutland
Currently we BUG() if we see a HSR.EC value we don't recognise. As configurable disables/enables are added to the architecture (controlled by RES1/RES0 bits respectively), with associated synchronous exceptions, it may be possible for a guest to trigger exceptions with classes that we don't recognise. While we can't service these exceptions in a manner useful to the guest, we can avoid bringing down the host. Per ARM DDI 0406C.c, all currently unallocated HSR EC encodings are reserved, and per ARM DDI 0487A.k_iss10775, page G6-4395, EC values within the range 0x00 - 0x2c are reserved for future use with synchronous exceptions, and EC values within the range 0x2d - 0x3f may be used for either synchronous or asynchronous exceptions. The patch makes KVM handle any unknown EC by injecting an UNDEFINED exception into the guest, with a corresponding (ratelimited) warning in the host dmesg. We could later improve on this with with a new (opt-in) exit to the host userspace. Cc: Dave Martin <dave.martin@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-17KVM: race-free exit from KVM_RUN without POSIX signalsPaolo Bonzini
The purpose of the KVM_SET_SIGNAL_MASK API is to let userspace "kick" a VCPU out of KVM_RUN through a POSIX signal. A signal is attached to a dummy signal handler; by blocking the signal outside KVM_RUN and unblocking it inside, this possible race is closed: VCPU thread service thread -------------------------------------------------------------- check flag set flag raise signal (signal handler does nothing) KVM_RUN However, one issue with KVM_SET_SIGNAL_MASK is that it has to take tsk->sighand->siglock on every KVM_RUN. This lock is often on a remote NUMA node, because it is on the node of a thread's creator. Taking this lock can be very expensive if there are many userspace exits (as is the case for SMP Windows VMs without Hyper-V reference time counter). As an alternative, we can put the flag directly in kvm_run so that KVM can see it: VCPU thread service thread -------------------------------------------------------------- raise signal signal handler set run->immediate_exit KVM_RUN check run->immediate_exit Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-08KVM: arm/arm64: Set a background timer to the earliest timer expirationJintack Lim
When scheduling a background timer, consider both of the virtual and physical timer and pick the earliest expiration time. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08KVM: arm/arm64: Initialize the emulated EL1 physical timerJintack Lim
Initialize the emulated EL1 physical timer with the default irq number. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08KVM: arm/arm64: Decouple kvm timer functions from virtual timerJintack Lim
Now that we have a separate structure for timer context, make functions generic so that they can work with any timer context, not just the virtual timer context. This does not change the virtual timer functionality. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08KVM: arm/arm64: Move cntvoff to each timer contextJintack Lim
Make cntvoff per each timer context. This is helpful to abstract kvm timer functions to work with timer context without considering timer types (e.g. physical timer or virtual timer). This also would pave the way for ever doing adjustments of the cntvoff on a per-CPU basis if that should ever make sense. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30arm/arm64: KVM: Get rid of KVM_MEMSLOT_INCOHERENTMarc Zyngier
KVM_MEMSLOT_INCOHERENT is not used anymore, as we've killed its only use in the arm/arm64 MMU code. Let's remove the last artifacts. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30arm/arm64: KVM: Stop propagating cacheability status of a faulted pageMarc Zyngier
Now that we unconditionally flush newly mapped pages to the PoC, there is no need to care about the "uncached" status of individual pages - they must all be visible all the way down. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Implement VGICv3 CPU interface accessVijaya Kumar K
VGICv3 CPU interface registers are accessed using KVM_DEV_ARM_VGIC_CPU_SYSREGS ioctl. These registers are accessed as 64-bit. The cpu MPIDR value is passed along with register id. It is used to identify the cpu for registers access. The VM that supports SEIs expect it on destination machine to handle guest aborts and hence checked for ICC_CTLR_EL1.SEIS compatibility. Similarly, VM that supports Affinity Level 3 that is required for AArch64 mode, is required to be supported on destination machine. Hence checked for ICC_CTLR_EL1.A3V compatibility. The arch/arm64/kvm/vgic-sys-reg-v3.c handles read and write of VGIC CPU registers for AArch64. For AArch32 mode, arch/arm/kvm/vgic-v3-coproc.c file is created but APIs are not implemented. Updated arch/arm/include/uapi/asm/kvm.h with new definitions required to compile for AArch32. The version of VGIC v3 specification is defined here Documentation/virtual/kvm/devices/arm-vgic-v3.txt Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-25KVM: arm/arm64: vgic: Add debugfs vgic-state fileChristoffer Dall
Add a file to debugfs to read the in-kernel state of the vgic. We don't do any locking of the entire VGIC state while traversing all the IRQs, so if the VM is running the user/developer may not see a quiesced state, but should take care to pause the VM using facilities in user space for that purpose. We also don't support LPIs yet, but they can be added easily if needed. Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-01-13KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systemsJintack Lim
Current KVM world switch code is unintentionally setting wrong bits to CNTHCTL_EL2 when E2H == 1, which may allow guest OS to access physical timer. Bit positions of CNTHCTL_EL2 are changing depending on HCR_EL2.E2H bit. EL1PCEN and EL1PCTEN are 1st and 0th bits when E2H is not set, but they are 11th and 10th bits respectively when E2H is set. In fact, on VHE we only need to set those bits once, not for every world switch. This is because the host kernel runs in EL2 with HCR_EL2.TGE == 1, which makes those bits have no effect for the host kernel execution. So we just set those bits once for guests, and that's it. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-14ARM: KVM: Support vGICv3 ITSVladimir Murzin
This patch allows to build and use vGICv3 ITS in 32-bit mode. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-04arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a ↵Marc Zyngier
single CPU Architecturally, TLBs are private to the (physical) CPU they're associated with. But when multiple vcpus from the same VM are being multiplexed on the same CPU, the TLBs are not private to the vcpus (and are actually shared across the VMID). Let's consider the following scenario: - vcpu-0 maps PA to VA - vcpu-1 maps PA' to VA If run on the same physical CPU, vcpu-1 can hit TLB entries generated by vcpu-0 accesses, and access the wrong physical page. The solution to this is to keep a per-VM map of which vcpu ran last on each given physical CPU, and invalidate local TLBs when switching to a different vcpu from the same VM. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>