Re: port-amd64/57661 (Crash when booting on Xeon Silver 4416+ in KVM/Qemu)

[riastradh%NetBSD.org@localhost]

Synopsis: Crash when booting on Xeon Silver 4416+ in KVM/Qemu

State-Changed-From-To: needs-pullups->pending-pullups
State-Changed-By: riastradh%NetBSD.org@localhost
State-Changed-When: Thu, 15 May 2025 12:45:55 +0000
State-Changed-Why:
Fixed in HEAD, and I have requested the following pullups for minimal
parts of the fix:

pullup-9 #1954 https://releng.netbsd.org/cgi-bin/req-9.cgi?show=1954
=> Just the change to x86/identcpu.c that limits XCR0 to the NetBSD-
   supported features before we query CPUID for the state size.

pullup-10 #1118 https://releng.netbsd.org/cgi-bin/req-10.cgi?show=1118
pullup-10 #1119 https://releng.netbsd.org/cgi-bin/req-10.cgi?show=1119
=> x86/identcpu.c change as for netbsd-9, and x86/fpu.c change to
   allocate adequate space for safe/zero FPU states if the save size
   exceeds 576 bytes (union savefpu)

I think this should be enough to fix the crashes on both branches,
without changing anything about how pcbs are allocated or adding support
for Intel AMX TILECFG/TILEDATA, but it would be good to test too on an
affected machine.