On Tue, 18 Dec 2018 at 14:00, Marc Zyngier <marc.zyng...@arm.com> wrote: > > On 12/12/2018 20:17, Dave Martin wrote: > > Since commit d26c25a9d19b ("arm64: KVM: Tighten guest core register > > access from userspace"), KVM_{GET,SET}_ONE_REG rejects register IDs > > that do not correspond to a single underlying architectural register. > > > > KVM_GET_REG_LIST was not changed to match however: instead, it > > simply yields a list of 32-bit register IDs that together cover the > > whole kvm_regs struct. This means that if userspace tries to use > > the resulting list of IDs directly to drive calls to KVM_*_ONE_REG, > > some of those calls will now fail. > > > > This was not the intention. Instead, iterating KVM_*_ONE_REG over > > the list of IDs returned by KVM_GET_REG_LIST should be guaranteed > > to work. > > > > This patch fixes the problem by splitting validate_core_reg_id() > > into a backend core_reg_size_from_offset() which does all of the > > work except for checking that the size field in the register ID > > matches, and kvm_arm_copy_reg_indices() and num_core_regs() are > > converted to use this to enumerate the valid offsets. > > > > kvm_arm_copy_reg_indices() now also sets the register ID size field > > appropriately based on the value returned, so the register ID > > supplied to userspace is fully qualified for use with the register > > access ioctls. > > > > Cc: sta...@vger.kernel.org > > Fixes: d26c25a9d19b ("arm64: KVM: Tighten guest core register access from > > userspace") > > Signed-off-by: Dave Martin <dave.mar...@arm.com> > > ---
> I'm quite keen on queuing this for 4.21, but I'd like Peter's seal of > approval on it. > > Peter? Sounds plausible, but I'm on holiday now til January, so if you want a more detailed response than that (or even actual testing with QEMU) it'll have to wait til next year. (Note that I never tested d26c25a9d19b with QEMU either...) thanks -- PMM _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm