Add KVM_CAP_GUEST_DEBUG_HW_BPS/WPS
#202
Conversation
michael2012z
requested review from
acatangiu,
alxiord,
andreeaflorescu,
lauralt and
sameo
as code owners
| assert!(kvm.get_guest_debug_hw_bps() >= 0); | ||
| assert!(kvm.get_guest_debug_hw_wps() >= 0); |
There was a problem hiding this comment.
To discuss:
I am not sure about the rule to check the result. The returned value vary on different machines. ">=0" seems not very meaningful.
And good idea?
There was a problem hiding this comment.
I think it's okay to check it as it is now in the test because we don't know what hosts we're running on. Can you add a comment about why we're doing the check this way? (i.e. different values on different platforms).
| /// | ||
| /// Returns 0 if the capability is not available and a positive integer otherwise. | ||
| #[cfg(target_arch = "aarch64")] | ||
| pub fn get_guest_debug_hw_wps(&self) -> i32 { |
There was a problem hiding this comment.
If there is increasing requirements to call the APIs that return a integer, is it good to expose check_extension_int itself?
There was a problem hiding this comment.
We can mark it as public as well, I don't have any concern with that. That's a good point!
There was a problem hiding this comment.
I added a commit for that.
| pub fn get_host_ipa_limit(&self) -> i32 { | ||
| self.check_extension_int(Cap::ArmVmIPASize) | ||
| } | ||
|
|
||
| /// AArch64 specific call to get the number of supported hardware breakpoints. | ||
| /// | ||
| /// Returns 0 if the capability is not available and a positive integer otherwise. |
There was a problem hiding this comment.
Does the integer bear any meaning? Can we return a bool in case it doesn't have any useful information?
There was a problem hiding this comment.
The integer is the number of breakpoints.
There was a problem hiding this comment.
The integer is useful in supporting the debug of guest kernel.
On x86, the max number of breakpoints is 4, while on arm the number is not fixed but is indicated by this API.
The API `KVM_CAP_GUEST_DEBUG_HW_BPS` and `KVM_CAP_GUEST_DEBUG_HW_WPS` are required to determine the number of supported guest debug registers. Signed-off-by: Michael Zhao <michael.zhao@arm.com>
The function is useful for checking the capabilities that return numbers rather than booleans. Signed-off-by: Michael Zhao <michael.zhao@arm.com>
michael2012z
force-pushed
the
aarch64-guest-debug
branch
from
cf25ee2
to
3cdd6e6
Compare
Summary of the PR
The API
KVM_CAP_GUEST_DEBUG_HW_BPSandKVM_CAP_GUEST_DEBUG_HW_WPSare required to determine the number of supported guest debug registers.
Requirements
Before submitting your PR, please make sure you addressed the following
requirements:
git commit -s), and the commitmessage has max 60 characters for the summary and max 75 characters for each
description line.
test.
unsafecode is properly documented.