[PATCH v1 4/4] x86/vmware: Run panic diagnostics before kdump by default

The core panic path enters a loaded crash kernel before running kmsg
dumpers, so the VMware logger cannot preserve the panic in the host log.
Set crash_kexec_post_notifiers during VMware platform setup. setup_arch()
runs before ordinary core parameters are parsed, so an explicit
crash_kexec_post_notifiers=0 still overrides this default. The 0644
parameter also remains writable at runtime.

VMware exposes no capability bit for this behavior, so the default changes
for every VMware guest. Running the logger first adds work to the panic
path and can reduce kdump reliability.

A full log transfer uses 1027 low-bandwidth hypercalls; three checkpoint
attempts are bounded at 3077. In vmcall tests, a maximum-size transfer
took at most 7.47 ms; three complete transfers comprising 3081 calls took
at most 21.58 ms.

The crash report remains suppressed while a crash kernel is loaded because
the host may terminate the VM inside that call. A future report from the
crash kernel or kdump userspace can restore the event after saving the
vmcore.

Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
---
 arch/x86/kernel/cpu/vmware.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index c21fc835537f..d88c625d8389 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c

@@ -646,6 +646,7 @@ static void __init vmware_platform_setup(void)
 {
 	u32 eax, ebx, ecx;
 	u64 lpj, tsc_khz;
+	crash_kexec_post_notifiers = true;
 
 	eax = vmware_hypercall3(VMWARE_CMD_GETHZ, UINT_MAX, &ebx, &ecx);
 

-- 
2.53.0