diff options
author | neel <neel@FreeBSD.org> | 2014-07-26 02:53:51 +0000 |
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committer | neel <neel@FreeBSD.org> | 2014-07-26 02:53:51 +0000 |
commit | 20e3e8762f23482453fd0cfba9aae28ab8287d23 (patch) | |
tree | 5210df9d99ccf6d6e69f126ce422e52cca1fc6e4 /sys/amd64/vmm | |
parent | 62d591cec94c248df911d92a4fe25355d10f687f (diff) | |
download | FreeBSD-src-20e3e8762f23482453fd0cfba9aae28ab8287d23.zip FreeBSD-src-20e3e8762f23482453fd0cfba9aae28ab8287d23.tar.gz |
If a vcpu has issued a HLT instruction with interrupts disabled then it sleeps
forever in vm_handle_hlt().
This is usually not an issue as long as one of the other vcpus properly resets
or powers off the virtual machine. However, if the bhyve(8) process is killed
with a signal the halted vcpu cannot be woken up because it's sleep cannot be
interrupted.
Fix this by waking up periodically and returning from vm_handle_hlt() if
TDF_ASTPENDING is set.
Reported by: Leon Dang
Sponsored by: Nahanni Systems
Diffstat (limited to 'sys/amd64/vmm')
-rw-r--r-- | sys/amd64/vmm/intel/vmx.c | 2 | ||||
-rw-r--r-- | sys/amd64/vmm/vmm.c | 10 |
2 files changed, 10 insertions, 2 deletions
diff --git a/sys/amd64/vmm/intel/vmx.c b/sys/amd64/vmm/intel/vmx.c index 4f82ea6..54b2998 100644 --- a/sys/amd64/vmm/intel/vmx.c +++ b/sys/amd64/vmm/intel/vmx.c @@ -2559,7 +2559,7 @@ vmx_run(void *arg, int vcpu, register_t startrip, pmap_t pmap, break; } - if (curthread->td_flags & (TDF_ASTPENDING | TDF_NEEDRESCHED)) { + if (vcpu_should_yield(vm, vcpu)) { enable_intr(); vm_exit_astpending(vmx->vm, vcpu, vmcs_guest_rip()); vmx_astpending_trace(vmx, vcpu, vmexit->rip); diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c index 78aefc4..397035a 100644 --- a/sys/amd64/vmm/vmm.c +++ b/sys/amd64/vmm/vmm.c @@ -1105,6 +1105,10 @@ vm_handle_hlt(struct vm *vm, int vcpuid, bool intr_disabled, bool *retu) } } + /* Don't go to sleep if the vcpu thread needs to yield */ + if (vcpu_should_yield(vm, vcpuid)) + break; + /* * Some Linux guests implement "halt" by having all vcpus * execute HLT with interrupts disabled. 'halted_cpus' keeps @@ -1128,7 +1132,11 @@ vm_handle_hlt(struct vm *vm, int vcpuid, bool intr_disabled, bool *retu) t = ticks; vcpu_require_state_locked(vcpu, VCPU_SLEEPING); - msleep_spin(vcpu, &vcpu->mtx, wmesg, 0); + /* + * XXX msleep_spin() cannot be interrupted by signals so + * wake up periodically to check pending signals. + */ + msleep_spin(vcpu, &vcpu->mtx, wmesg, hz); vcpu_require_state_locked(vcpu, VCPU_FROZEN); vmm_stat_incr(vm, vcpuid, VCPU_IDLE_TICKS, ticks - t); } |