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path: root/arch/arm/include/asm/kvm_hyp.h
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2019-02-19KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systemsChristoffer Dall
VHE systems don't have to emulate the physical timer, we can simply assign the EL1 physical timer directly to the VM as the host always uses the EL2 timers. In order to minimize the amount of cruft, AArch32 gets definitions for the physical timer too, but is should be generally unused on this architecture. Co-written with Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2018-03-19KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQsChristoffer Dall
We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19KVM: arm/arm64: Move VGIC APR save/restore to vgic put/loadChristoffer Dall
The APRs can only have bits set when the guest acknowledges an interrupt in the LR and can only have a bit cleared when the guest EOIs an interrupt in the LR. Therefore, if we have no LRs with any pending/active interrupts, the APR cannot change value and there is no need to clear it on every exit from the VM (hint: it will have already been cleared when we exited the guest the last time with the LRs all EOIed). The only case we need to take care of is when we migrate the VCPU away from a CPU or migrate a new VCPU onto a CPU, or when we return to userspace to capture the state of the VCPU for migration. To make sure this works, factor out the APR save/restore functionality into separate functions called from the VCPU (and by extension VGIC) put/load hooks. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-01-08arm: KVM: Add optimized PIPT icache flushingMarc Zyngier
Calling __cpuc_coherent_user_range to invalidate the icache on a PIPT icache machine has some pointless overhead, as it starts by cleaning the dcache to the PoU, while we're guaranteed to have already cleaned it to the PoC. As KVM is the only user of such a feature, let's implement some ad-hoc cache flushing in kvm_mmu.h. Should it become useful to other subsystems, it can be moved to a more global location. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-08KVM: arm/arm64: Detangle kvm_mmu.h from kvm_hyp.hMarc Zyngier
kvm_hyp.h has an odd dependency on kvm_mmu.h, which makes the opposite inclusion impossible. Let's start with breaking that useless dependency. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06KVM: arm/arm64: Move timer save/restore out of the hyp codeChristoffer Dall
As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-07-12ARM: KVM: move asmlinkage before typeJoe Perches
asmlinkage is either 'extern "C"' or blank. Move the uses of asmlinkage before the return types to be similar to the rest of the kernel. Link: http://lkml.kernel.org/r/005b8e120650c6a13b541e420f4e3605603fe9e6.1499284835.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2016-09-22ARM: KVM: Support vgic-v3Vladimir Murzin
This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22ARM: Move system register accessors to asm/cp15.hVladimir Murzin
Headers linux/irqchip/arm-gic.v3.h and arch/arm/include/asm/kvm_hyp.h are included in virt/kvm/arm/hyp/vgic-v3-sr.c and both define macros called __ACCESS_CP15 and __ACCESS_CP15_64 which obviously creates a conflict. These macros were introduced independently for GIC and KVM and, in fact, do the same thing. As an option we could add prefixes to KVM and GIC version of macros so they won't clash, but it'd introduce code duplication. Alternatively, we could keep macro in, say, GIC header and include it in KVM one (or vice versa), but such dependency would not look nicer. So we follow arm64 way (it handles this via sysreg.h) and move only single set of macros to asm/cp15.h Cc: Russell King <rmk+kernel@armlinux.org.uk> 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>
2016-07-03arm/arm64: Get rid of KERN_TO_HYPMarc Zyngier
We have both KERN_TO_HYP and kern_hyp_va, which do the exact same thing. Let's standardize on the latter. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-03arm/arm64: KVM: Remove hyp_kern_va helperMarc Zyngier
hyp_kern_va is now completely unused, so let's remove it entirely. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-02-29ARM: KVM: Use common version of timer-sr.cMarc Zyngier
Using the common HYP timer code is a bit more tricky, since we use system register names. Nothing a set of macros cannot work around... Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29ARM: KVM: Move kvm/hyp/hyp.h to include/asm/kvm_hyp.hMarc Zyngier
In order to be able to use the code located in virt/kvm/arm/hyp, we need to make the global hyp.h file accessible from include/asm, similar to what we did for arm64. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>