Add ability to debug additional registers via gdb #817
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Signed-off-by: James Sturtevant <[email protected]>
Signed-off-by: James Sturtevant <[email protected]>
jsturtevant
added
the
kind/enhancement
dblnz
reviewed
Aug 25, 2025
| @@ -193,6 +194,31 @@ impl GuestDebug for KvmDebug { | |||
| regs.rip = vcpu_regs.rip; | |||
| regs.rflags = vcpu_regs.rflags; | |||
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| // Read XMM registers from FPU state | |||
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Suggested change
| // Read XMM registers from FPU state | |
| // Read XMM registers from FPU state |
| match vcpu_fd.get_xsave() { | ||
| Ok(xsave) => { | ||
| regs.mxcsr = xsave.region[6]; | ||
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| @@ -16,6 +16,7 @@ limitations under the License. | |||
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| use std::collections::HashMap; | |||
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| use gdbstub_arch::msp430::reg; | |||
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I think this is not needed, right?
| @@ -258,6 +270,8 @@ impl GuestDebug for MshvDebug { | |||
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| rip: regs.rip, | |||
| rflags: regs.rflags, | |||
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| @@ -258,6 +270,8 @@ impl GuestDebug for MshvDebug { | |||
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| rip: regs.rip, | |||
| rflags: regs.rflags, | |||
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| @@ -591,6 +591,9 @@ impl Hypervisor for KVMDriver { | |||
| mxcsr: MXCSR_DEFAULT, | |||
| ..Default::default() // zero out the rest | |||
| }; | |||
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| // note kvm set_fpu doesn't actually set or read the mxcsr value | |||
| // https://elixir.bootlin.com/linux/v6.16/source/arch/x86/kvm/x86.c#L12229 | |||
| self.vcpu_fd.set_fpu(&fpu)?; | |||
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How could we change the code to set/read the mxcsr value?
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This pull request adds support for reading and writing XMM and MXCSR registers in the GDB debug interface for all supported hypervisors (KVM, MSHV, and WHVP). It introduces new fields to the register structures to hold these values and implements the necessary logic to fetch and store them using each hypervisor's API.
Register structure updates:
xmm: [u128; 16]andmxcsr: u32fields to theX86_64Regsstruct to store XMM registers and MXCSR control state.Todo: