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2014-07-11ARM: KVM: __kvm_vcpu_run function return result fix in BE caseVictor Kamensky1-0/+5
The __kvm_vcpu_run function returns a 64-bit result in two registers, which has to be adjusted for BE case. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11ARM: KVM: handle 64bit values passed to mrcc or from mcrr instructions in BE caseVictor Kamensky1-2/+2
In some cases the mcrr and mrrc instructions in combination with the ldrd and strd instructions need to deal with 64bit value in memory. The ldrd and strd instructions already handle endianness within word (register) boundaries but to get effect of the whole 64bit value represented correctly, rr_lo_hi macro is introduced and is used to swap registers positions when the mcrr and mrrc instructions are used. That has the effect of swapping two words. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-02-27arm/arm64: KVM: detect CPU reset on CPU_PM_EXITMarc Zyngier1-1/+10
Commit 1fcf7ce0c602 (arm: kvm: implement CPU PM notifier) added support for CPU power-management, using a cpu_notifier to re-init KVM on a CPU that entered CPU idle. The code assumed that a CPU entering idle would actually be powered off, loosing its state entierely, and would then need to be reinitialized. It turns out that this is not always the case, and some HW performs CPU PM without actually killing the core. In this case, we try to reinitialize KVM while it is still live. It ends up badly, as reported by Andre Przywara (using a Calxeda Midway): [ 3.663897] Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x685760 [ 3.663897] unexpected data abort in Hyp mode at: 0xc067d150 [ 3.663897] unexpected HVC/SVC trap in Hyp mode at: 0xc0901dd0 The trick here is to detect if we've been through a full re-init or not by looking at HVBAR (VBAR_EL2 on arm64). This involves implementing the backend for __hyp_get_vectors in the main KVM HYP code (rather small), and checking the return value against the default one when the CPU notifier is called on CPU_PM_EXIT. Reported-by: Andre Przywara <osp@andrep.de> Tested-by: Andre Przywara <osp@andrep.de> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Rob Herring <rob.herring@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-05Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds1-2/+2
Pull ARM updates from Russell King: "This set includes adding support for Neon acceleration of RAID6 XOR code from Ard Biesheuvel, cache flushing and barrier updates from Will Deacon, and a cleanup to the ARM debug code which reduces the amount of code by about 500 lines. A few other cleanups, such as constifying the machine descriptors which already shouldn't be written to, cleaning up the printing of the L2 cache size" * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (55 commits) ARM: 7826/1: debug: support debug ll on hisilicon soc ARM: 7830/1: delay: don't bother reporting bogomips in /proc/cpuinfo ARM: 7829/1: Add ".text.unlikely" and ".text.hot" to arm unwind tables ARM: 7828/1: ARMv7-M: implement restart routine common to all v7-M machines ARM: 7827/1: highbank: fix debug uart virtual address for LPAE ARM: 7823/1: errata: workaround Cortex-A15 erratum 773022 ARM: 7806/1: allow DEBUG_UNCOMPRESS for Tegra ARM: 7793/1: debug: use generic option for ep93xx PL10x debug port ARM: debug: move SPEAr debug to generic PL01x code ARM: debug: move davinci debug to generic 8250 code ARM: debug: move keystone debug to generic 8250 code ARM: debug: remove DEBUG_ROCKCHIP_UART ARM: debug: provide generic option choices for 8250 and PL01x ports ARM: debug: move PL01X debug include into arch/arm/include/debug/ ARM: debug: provide PL01x debug uart phys/virt address configuration options ARM: debug: add support for word accesses to debug/8250.S ARM: debug: move 8250 debug include into arch/arm/include/debug/ ARM: debug: provide 8250 debug uart phys/virt address configuration options ARM: debug: provide 8250 debug uart register shift configuration option ARM: debug: provide 8250 debug uart flow control configuration option ...
2013-08-30ARM: KVM: Add newlines to panic stringsChristoffer Dall1-4/+4
The panic strings are hard to read and on narrow terminals some characters are simply truncated off the panic message. Make is slightly prettier with a newline in the Hyp panic strings. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-08-12ARM: kvm: use inner-shareable barriers after TLB flushingWill Deacon1-2/+2
When flushing the TLB at PL2 in response to remapping at stage-2 or VMID rollover, we have a dsb instruction to ensure completion of the command before continuing. Since we only care about other processors for TLB invalidation, use the inner-shareable variant of the dsb instruction instead. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-06-26ARM: KVM: clear exclusive monitor on all exception returnsMarc Zyngier1-0/+3
Make sure we clear the exclusive monitor on all exception returns, which otherwise could lead to lock corruptions. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26ARM: KVM: add missing dsb before invalidating Stage-2 TLBsMarc Zyngier1-0/+1
When performing a Stage-2 TLB invalidation, it is necessary to make sure the write to the page tables is observable by all CPUs. For this purpose, add a dsb instruction to __kvm_tlb_flush_vmid_ipa before doing the TLB invalidation itself. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-06-26ARM: KVM: perform save/restore of PARMarc Zyngier1-1/+11
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>
2013-03-06ARM: KVM: change kvm_tlb_flush_vmid to kvm_tlb_flush_vmid_ipaMarc Zyngier1-3/+6
v8 is capable of invalidating Stage-2 by IPA, but v7 is not. Change kvm_tlb_flush_vmid() to take an IPA parameter, which is then ignored by the invalidation code (and nuke the whole TLB as it always did). This allows v8 to implement a more optimized strategy. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-03-06KVM: ARM: Fix wrong address in commentJonghwan Choi1-2/+2
hyp_hvc vector offset is 0x14 and hyp_svc vector offset is 0x8. Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
2013-02-11ARM: KVM: arch_timers: Add guest timer core supportMarc Zyngier1-0/+2
Add some the architected timer related infrastructure, and support timer interrupt injection, which can happen as a resultof three possible events: - The virtual timer interrupt has fired while we were still executing the guest - The timer interrupt hasn't fired, but it expired while we were doing the world switch - A hrtimer we programmed earlier has fired 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>
2013-02-11ARM: KVM: Initial VGIC infrastructure codeMarc Zyngier1-0/+4
Wire the basic framework code for VGIC support and the initial in-kernel MMIO support code for the VGIC, used for the distributor emulation. 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: World-switch implementationChristoffer Dall1-3/+393
Provides complete world-switch implementation to switch to other guests running in non-secure modes. Includes Hyp exception handlers that capture necessary exception information and stores the information on the VCPU and KVM structures. The following Hyp-ABI is also documented in the code: Hyp-ABI: Calling HYP-mode functions from host (in SVC mode): Switching to Hyp mode is done through a simple HVC #0 instruction. The exception vector code will check that the HVC comes from VMID==0 and if so will push the necessary state (SPSR, lr_usr) on the Hyp stack. - r0 contains a pointer to a HYP function - r1, r2, and r3 contain arguments to the above function. - The HYP function will be called with its arguments in r0, r1 and r2. On HYP function return, we return directly to SVC. A call to a function executing in Hyp mode is performed like the following: <svc code> ldr r0, =BSYM(my_hyp_fn) ldr r1, =my_param hvc #0 ; Call my_hyp_fn(my_param) from HYP mode <svc code> Otherwise, the world-switch is pretty straight-forward. All state that can be modified by the guest is first backed up on the Hyp stack and the VCPU values is loaded onto the hardware. State, which is not loaded, but theoretically modifiable by the guest is protected through the virtualiation features to generate a trap and cause software emulation. Upon guest returns, all state is restored from hardware onto the VCPU struct and the original state is restored from the Hyp-stack onto the hardware. SMP support using the VMPIDR calculated on the basis of the host MPIDR and overriding the low bits with KVM vcpu_id contributed by Marc Zyngier. Reuse of VMIDs has been implemented by Antonios Motakis and adapated from a separate patch into the appropriate patches introducing the functionality. Note that the VMIDs are stored per VM as required by the ARM architecture reference manual. To support VFP/NEON we trap those instructions using the HPCTR. When we trap, we switch the FPU. After a guest exit, the VFP state is returned to the host. When disabling access to floating point instructions, we also mask FPEXC_EN in order to avoid the guest receiving Undefined instruction exceptions before we have a chance to switch back the floating point state. We are reusing vfp_hard_struct, so we depend on VFPv3 being enabled in the host kernel, if not, we still trap cp10 and cp11 in order to inject an undefined instruction exception whenever the guest tries to use VFP/NEON. VFP/NEON developed by Antionios Motakis and Rusty Russell. Aborts that are permission faults, and not stage-1 page table walk, do not report the faulting address in the HPFAR. We have to resolve the IPA, and store it just like the HPFAR register on the VCPU struct. If the IPA cannot be resolved, it means another CPU is playing with the page tables, and we simply restart the guest. This quirk was fixed by Marc Zyngier. 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: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Memory virtualization setupChristoffer Dall1-0/+7
This commit introduces the framework for guest memory management through the use of 2nd stage translation. Each VM has a pointer to a level-1 table (the pgd field in struct kvm_arch) which is used for the 2nd stage translations. Entries are added when handling guest faults (later patch) and the table itself can be allocated and freed through the following functions implemented in arch/arm/kvm/arm_mmu.c: - kvm_alloc_stage2_pgd(struct kvm *kvm); - kvm_free_stage2_pgd(struct kvm *kvm); Each entry in TLBs and caches are tagged with a VMID identifier in addition to ASIDs. The VMIDs are assigned consecutively to VMs in the order that VMs are executed, and caches and tlbs are invalidated when the VMID space has been used to allow for more than 255 simultaenously running guests. The 2nd stage pgd is allocated in kvm_arch_init_vm(). The table is freed in kvm_arch_destroy_vm(). Both functions are called from the main KVM code. We pre-allocate page table memory to be able to synchronize using a spinlock and be called under rcu_read_lock from the MMU notifiers. We steal the mmu_memory_cache implementation from x86 and adapt for our specific usage. We support MMU notifiers (thanks to Marc Zyngier) through kvm_unmap_hva and kvm_set_spte_hva. Finally, define kvm_phys_addr_ioremap() to map a device at a guest IPA, which is used by VGIC support to map the virtual CPU interface registers to the guest. This support is added by Marc Zyngier. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Hypervisor initializationChristoffer Dall1-0/+62
Sets up KVM code to handle all exceptions taken to Hyp mode. When the kernel is booted in Hyp mode, calling an hvc instruction with r0 pointing to the new vectors, the HVBAR is changed to the the vector pointers. This allows subsystems (like KVM here) to execute code in Hyp-mode with the MMU disabled. We initialize other Hyp-mode registers and enables the MMU for Hyp-mode from the id-mapped hyp initialization code. Afterwards, the HVBAR is changed to point to KVM Hyp vectors used to catch guest faults and to switch to Hyp mode to perform a world-switch into a KVM guest. Also provides memory mapping code to map required code pages, data structures, and I/O regions accessed in Hyp mode at the same virtual address as the host kernel virtual addresses, but which conforms to the architectural requirements for translations in Hyp mode. This interface is added in arch/arm/kvm/arm_mmu.c and comprises: - create_hyp_mappings(from, to); - create_hyp_io_mappings(from, to, phys_addr); - free_hyp_pmds(); Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-23KVM: ARM: Initial skeleton to compile KVM supportChristoffer Dall1-0/+19
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>