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author | Andre Przywara <andre.przywara@arm.com> | 2015-12-02 01:36:37 +0300 |
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committer | Christoffer Dall <christoffer.dall@linaro.org> | 2016-05-20 16:40:03 +0300 |
commit | 7d450e2821710718fd6703e9c486249cee913bab (patch) | |
tree | 02dc0e9f84440e3d77ee72f32e27d53bcedda758 /virt/kvm/arm/vgic/vgic.h | |
parent | c3199f28e09496aa9fec9313b4f6e90e7dc913f0 (diff) | |
download | linux-7d450e2821710718fd6703e9c486249cee913bab.tar.xz |
KVM: arm/arm64: vgic-new: Add userland access to VGIC dist registers
Userland may want to save and restore the state of the in-kernel VGIC,
so we provide the code which takes a userland request and translate
that into calls to our MMIO framework.
From Christoffer:
When accessing the VGIC state from userspace we really don't want a VCPU
to be messing with the state at the same time, and the API specifies
that we should return -EBUSY if any VCPUs are running.
Check and prevent VCPUs from running by grabbing their mutexes, one by
one, and error out if we fail.
(Note: This could potentially be simplified to just do a simple check
and see if any VCPUs are running, and return -EBUSY then, without
enforcing the locking throughout the duration of the uaccess, if we
think that taking/releasing all these mutexes for every single GIC
register access is too heavyweight.)
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic.h')
0 files changed, 0 insertions, 0 deletions