diff options
| author | Alex Bennée <alex.bennee@linaro.org> | 2015-07-07 18:29:58 +0200 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2015-07-21 13:47:08 +0200 |
| commit | 337b99bf7edfb2044781447e7ca386edb1fdba9d (patch) | |
| tree | 0fb8c4deaaa6dcffa7ce8814b78b8e3d0eb36360 /arch/arm64/kvm/guest.c | |
| parent | KVM: arm64: guest debug, add SW break point support (diff) | |
| download | linux-337b99bf7edfb2044781447e7ca386edb1fdba9d.tar.xz linux-337b99bf7edfb2044781447e7ca386edb1fdba9d.zip | |
KVM: arm64: guest debug, add support for single-step
This adds support for single-stepping the guest. To do this we need to
manipulate the guests PSTATE.SS and MDSCR_EL1.SS bits to trigger
stepping. We take care to preserve MDSCR_EL1 and trap access to it to
ensure we don't affect the apparent state of the guest.
As we have to enable trapping of all software debug exceptions we
suppress the ability of the guest to single-step itself. If we didn't we
would have to deal with the exception arriving while the guest was in
kernelspace when the guest is expecting to single-step userspace. This
is something we don't want to unwind in the kernel. Once the host is no
longer debugging the guest its ability to single-step userspace is
restored.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/kvm/guest.c')
| -rw-r--r-- | arch/arm64/kvm/guest.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 22d22c54fd8d..48de4f4aaa1a 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -332,7 +332,9 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, return -EINVAL; } -#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP) +#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ + KVM_GUESTDBG_USE_SW_BP | \ + KVM_GUESTDBG_SINGLESTEP) /** * kvm_arch_vcpu_ioctl_set_guest_debug - set up guest debugging |