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path: root/arch/arm64/kvm/sys_regs.c
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2014-05-09arm64: barriers: make use of barrier options with explicit barriersWill Deacon
When calling our low-level barrier macros directly, we can often suffice with more relaxed behaviour than the default "all accesses, full system" option. This patch updates the users of dsb() to specify the option which they actually require. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-03arm64: KVM: flush VM pages before letting the guest enable cachesMarc Zyngier
When the guest runs with caches disabled (like in an early boot sequence, for example), all the writes are diectly going to RAM, bypassing the caches altogether. Once the MMU and caches are enabled, whatever sits in the cache becomes suddenly visible, which isn't what the guest expects. A way to avoid this potential disaster is to invalidate the cache when the MMU is being turned on. For this, we hook into the SCTLR_EL1 trapping code, and scan the stage-2 page tables, invalidating the pages/sections that have already been mapped in. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03arm64: 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> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-03-03arm64: KVM: allows discrimination of AArch32 sysreg accessMarc Zyngier
The current handling of AArch32 trapping is slightly less than perfect, as it is not possible (from a handler point of view) to distinguish it from an AArch64 access, nor to tell a 32bit from a 64bit access either. Fix this by introducing two additional flags: - is_aarch32: true if the access was made in AArch32 mode - is_32bit: true if is_aarch32 == true and a MCR/MRC instruction was used to perform the access (as opposed to MCRR/MRRC). This allows a handler to cover all the possible conditions in which a system register gets trapped. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-08-09arm64: KVM: perform save/restore of PAR_EL1Marc Zyngier
Not saving PAR_EL1 is an unfortunate oversight. If the guest performs an AT* operation and gets scheduled out before reading the result of the translation from PAREL1, 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. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-06-12arm64: KVM: 32bit handling of coprocessor trapsMarc Zyngier
Provide the necessary infrastructure to trap coprocessor accesses that occur when running 32bit guests. Also wire SMC and HVC trapped in 32bit mode while were at it. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-06-07arm64: KVM: system register handlingMarc Zyngier
Provide 64bit system register handling, modeled after the cp15 handling for ARM. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>