On 9/8/26 11:07 AM, Zack Rusin wrote: > A virtual machine may have neither guest-local persistent storage nor > working userspace after a panic. The host's vmware.log remains available > after the VM terminates, and a production encrypted guest is the only > component able to export readable panic text. Hyper-V already provides > this class of host-persistent panic reporting. > > Add a panic-only VMware logger that copies the newest 4 KiB of the kernel > log and sends it with bounded low-bandwidth RPC work. Ordinary guests > enable text transfer by default; encrypted guests require an administrator > to opt in through kernel.vmware_record_panic_msg. A separate late dumper > reports the structured crash event after built-in dumpers and suppresses > the event while a crash kernel is loaded, because a configured VMware host > may terminate the VM before the reporting hypercall returns. > > Patch 4 makes panic diagnostics run before kdump by default on VMware > guests. This follows existing platform uses of > crash_kexec_post_notifiers, with Hyper-V as the closest guest-reporting > precedent. Unlike Hyper-V, VMware exposes no capability bit for this > behavior. An explicit crash_kexec_post_notifiers=0 still wins, and patch 4 > can be dropped without affecting patches 1 through 3. > > This replaces patches 2 and 3 of Alexey's v2 posting: > https://lore.kernel.org/all/[email protected]/ > > The intended merge path is tip's x86/vmware branch. Boris please review the > VMware transport and policy. Petr and John, please review the panic-only > dumper use and registration ordering. Joel and Kees, please review the > sysctl. Baoquan and the KEXEC/KDUMP team, please review the > loaded-crash-kernel guard and the default in patch 4. > > Zack Rusin (4): > x86/vmware: Add a bounded panic log sender > x86/vmware: Add the vmware_record_panic_msg sysctl > x86/vmware: Report guest crashes after kmsg dumpers > x86/vmware: Run panic diagnostics before kdump by default > > Documentation/admin-guide/sysctl/kernel.rst | 14 ++ > arch/x86/include/asm/vmware.h | 2 + > arch/x86/kernel/cpu/vmware.c | 245 ++++++++++++++++++++ > 3 files changed, 261 insertions(+) > > > base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
LGTM for the series Reviewed-by: Maaz Mombasawala <[email protected]> -- Maaz Mombasawala <[email protected]>
