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authorAlex Bennée <alex.bennee@linaro.org>2015-07-07 17:29:57 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2015-07-21 12:47:08 +0100
commit4bd611ca60afa155bca25b40312ed61c4d46237f (patch)
treef90c63e79179c6ce52a2dee5f7e05a14e7d9ce62 /Documentation/virtual
parent56c7f5e77f797fd0dcf2376ce1496f4238e6be33 (diff)
downloadlinux-4bd611ca60afa155bca25b40312ed61c4d46237f.tar.bz2
KVM: arm64: guest debug, add SW break point support
This adds support for SW breakpoints inserted by userspace. We do this by trapping all guest software debug exceptions to the hypervisor (MDCR_EL2.TDE). The exit handler sets an exit reason of KVM_EXIT_DEBUG with the kvm_debug_exit_arch structure holding the exception syndrome information. It will be up to userspace to extract the PC (via GET_ONE_REG) and determine if the debug event was for a breakpoint it inserted. If not userspace will need to re-inject the correct exception restart the hypervisor to deliver the debug exception to the guest. Any other guest software debug exception (e.g. single step or HW assisted breakpoints) will cause an error and the VM to be killed. This is addressed by later patches which add support for the other debug types. 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 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt2
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 19adfd385882..0f498da354f2 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2693,7 +2693,7 @@ when running. Common control bits are:
The top 16 bits of the control field are architecture specific control
flags which can include the following:
- - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86]
+ - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64]
- KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390]
- KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86]
- KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86]