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path: root/arch/arm/kvm/coproc.c
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2015-01-29arm/arm64: KVM: Use set/way op trapping to track the state of the cachesMarc Zyngier
Trying to emulate the behaviour of set/way cache ops is fairly pointless, as there are too many ways we can end-up missing stuff. Also, there is some system caches out there that simply ignore set/way operations. So instead of trying to implement them, let's convert it to VA ops, and use them as a way to re-enable the trapping of VM ops. That way, we can detect the point when the MMU/caches are turned off, and do a full VM flush (which is what the guest was trying to do anyway). This allows a 32bit zImage to boot on the APM thingy, and will probably help bootloaders in general. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-08-27KVM: ARM/arm64: avoid returning negative error code as boolWill Deacon
is_valid_cache returns true if the specified cache is valid. Unfortunately, if the parameter passed it out of range, we return -ENOENT, which ends up as true leading to potential hilarity. This patch returns false on the failure path instead. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-07-11ARM: KVM: one_reg coproc set and get BE fixesVictor Kamensky
Fix code that handles KVM_SET_ONE_REG, KVM_GET_ONE_REG ioctls to work in BE image. Before this fix get/set_one_reg functions worked correctly only in LE case - reg_from_user was taking 'void *' kernel address that actually could be target/source memory of either 4 bytes size or 8 bytes size, and code copied from/to user memory that could hold either 4 bytes register, 8 byte register or pair of 4 bytes registers. In order to work in endian agnostic way reg_from_user to reg_to_user functions should copy register value only to kernel variable with size that matches register size. In few place where size mismatch existed fix issue on macro caller side. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-03-03ARM: KVM: trap VM system registers until MMU and caches are ONMarc Zyngier
In order to be able to detect the point where the guest enables its MMU and caches, trap all the VM related system registers. Once we see the guest enabling both the MMU and the caches, we can go back to a saner mode of operation, which is to leave these registers in complete control of the guest. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03ARM: KVM: add world-switch for AMAIR{0,1}Marc Zyngier
HCR.TVM traps (among other things) accesses to AMAIR0 and AMAIR1. In order to minimise the amount of surprise a guest could generate by trying to access these registers with caches off, add them to the list of registers we switch/handle. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-03ARM: KVM: fix handling of trapped 64bit coprocessor accessesMarc Zyngier
Commit 240e99cbd00a (ARM: KVM: Fix 64-bit coprocessor handling) changed the way we match the 64bit coprocessor access from user space, but didn't update the trap handler for the same set of registers. The effect is that a trapped 64bit access is never matched, leading to a fault being injected into the guest. This went unnoticed as we didn't really trap any 64bit register so far. Placing the CRm field of the access into the CRn field of the matching structure fixes the problem. Also update the debug feature to emit the expected string in case of failing match. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2013-10-22ARM: KVM: fix L2CTLR to be per-clusterMarc Zyngier
The L2CTLR register contains the number of CPUs in this cluster. Make sure the register content is actually relevant to the vcpu that is being configured by computing the number of cores that are part of its cluster. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-22ARM: KVM: Fix MPIDR computing to support virtual clustersMarc Zyngier
In order to be able to support more than 4 A7 or A15 CPUs, we need to fix the MPIDR computing to reflect the fact that both A15 and A7 can only exist in clusters of at most 4 CPUs. Fix the MPIDR computing to allow virtual clusters to be exposed to the guest. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-10-12KVM: ARM: Add support for Cortex-A7Jonathan Austin
This patch adds support for running Cortex-A7 guests on Cortex-A7 hosts. As Cortex-A7 is architecturally compatible with A15, this patch is largely just generalising existing code. Areas where 'implementation defined' behaviour is identical for A7 and A15 is moved to allow it to be used by both cores. The check to ensure that coprocessor register tables are sorted correctly is also moved in to 'common' code to avoid each new cpu doing its own check (and possibly forgetting to do so!) Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-08-06ARM: KVM: Fix 64-bit coprocessor handlingChristoffer Dall
The PAR was exported as CRn == 7 and CRm == 0, but in fact the primary coprocessor register number was determined by CRm for 64-bit coprocessor registers as the user space API was modeled after the coprocessor access instructions (see the ARM ARM rev. C - B3-1445). However, just changing the CRn to CRm breaks the sorting check when booting the kernel, because the internal kernel logic always treats CRn as the primary register number, and it makes the table sorting impossible to understand for humans. Alternatively we could change the logic to always have CRn == CRm, but that becomes unclear in the number of ways we do look up of a coprocessor register. We could also have a separate 64-bit table but that feels somewhat over-engineered. Instead, keep CRn the primary representation of the primary coproc. register number in-kernel and always export the primary number as CRm as per the existing user space ABI. Note: The TTBR registers just magically worked because they happened to follow the CRn(0) regs and were considered CRn(0) in the in-kernel representation. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26ARM: KVM: perform save/restore of PARMarc Zyngier
Not saving PAR is an unfortunate oversight. If the guest performs an AT* operation and gets scheduled out before reading the result of the translation from PAR, it could become corrupted by another guest or the host. Saving this register is made slightly more complicated as KVM also uses it on the permission fault handling path, leading to an ugly "stash and restore" sequence. Fortunately, this is already a slow path so we don't really care. Also, Linux doesn't do any AT* operation, so Linux guests are not impacted by this bug. [ Slightly tweaked to use an even register as first operand to ldrd and strd operations in interrupts_head.S - Christoffer ] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-05-02Merge branches 'devel-stable', 'entry', 'fixes', 'mach-types', 'misc' and ↵Russell King
'smp-hotplug' into for-linus
2013-04-17ARM: KVM: fix unbalanced get_cpu() in access_dcswMarc Zyngier
In the very unlikely event where a guest would be foolish enough to *read* from a write-only cache maintainance register, we end up with preemption disabled, due to a misplaced get_cpu(). Just move the "is_write" test outside of the critical section. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-06ARM: KVM: abstract IL decoding awayMarc Zyngier
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-03-06ARM: KVM: abstract fault register accessesMarc Zyngier
Instead of directly accessing the fault registers, use proper accessors so the core code can be shared. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06ARM: KVM: convert GP registers from u32 to unsigned longMarc Zyngier
On 32bit ARM, unsigned long is guaranteed to be a 32bit quantity. On 64bit ARM, it is a 64bit quantity. In order to be able to share code between the two architectures, convert the registers to be unsigned long, so the core code can be oblivious of the change. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-02-11ARM: KVM: arch_timers: Add timer world switchMarc Zyngier
Do the necessary save/restore dance for the timers in the world switch code. In the process, allow the guest to read the physical counter, which is useful for its own clock_event_device. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-01-23KVM: ARM: VFP userspace interfaceRusty Russell
We use space #18 for floating point regs. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Demux CCSIDR in the userspace APIChristoffer Dall
The Cache Size Selection Register (CSSELR) selects the current Cache Size ID Register (CCSIDR). You write which cache you are interested in to CSSELR, and read the information out of CCSIDR. Which cache numbers are valid is known by reading the Cache Level ID Register (CLIDR). To export this state to userspace, we add a KVM_REG_ARM_DEMUX numberspace (17), which uses 8 bits to represent which register is being demultiplexed (0 for CCSIDR), and the lower 8 bits to represent this demultiplexing (in our case, the CSSELR value, which is 4 bits). Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: User space API for getting/setting co-proc registersChristoffer Dall
The following three ioctls are implemented: - KVM_GET_REG_LIST - KVM_GET_ONE_REG - KVM_SET_ONE_REG Now we have a table for all the cp15 registers, we can drive a generic API. The register IDs carry the following encoding: ARM registers are mapped using the lower 32 bits. The upper 16 of that is the register group type, or coprocessor number: ARM 32-bit CP15 registers have the following id bit patterns: 0x4002 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> ARM 64-bit CP15 registers have the following id bit patterns: 0x4003 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> For futureproofing, we need to tell QEMU about the CP15 registers the host lets the guest access. It will need this information to restore a current guest on a future CPU or perhaps a future KVM which allow some of these to be changed. We use a separate table for these, as they're only for the userspace API. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Emulation framework and CP15 emulationChristoffer Dall
Adds a new important function in the main KVM/ARM code called handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns from guest execution. This function examines the Hyp-Syndrome-Register (HSR), which contains information telling KVM what caused the exit from the guest. Some of the reasons for an exit are CP15 accesses, which are not allowed from the guest and this commit handles these exits by emulating the intended operation in software and skipping the guest instruction. Minor notes about the coproc register reset: 1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our table, at cost of 4 bytes per vcpu. 2) Added comments on the table indicating how we handle each register, for simplicity of understanding. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Initial skeleton to compile KVM supportChristoffer Dall
Targets KVM support for Cortex A-15 processors. Contains all the framework components, make files, header files, some tracing functionality, and basic user space API. Only supported core is Cortex-A15 for now. Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>