On 6/20/24 17:23, Ashish Kalra wrote: > From: Ashish Kalra <ashish.kalra@xxxxxxx> > > Accessing guest video memory/RAM in the decompressor causes guest > termination as the boot stage2 #VC handler for SEV-ES/SNP systems does > not support MMIO handling. > > This issue is observed during a SEV-ES/SNP guest kexec as kexec -c adds > screen_info to the boot parameters passed to the second kernel, which > causes console output to be dumped to both video and serial. > > As the decompressor output gets cleared really fast, it is preferable to > get the console output only on serial, hence, skip accessing the video > RAM during decompressor stage to prevent guest termination. > > Serial console output during decompressor stage works as boot stage2 #VC > handler already supports handling port I/O. > > [ bp: Massage. ] > > Suggested-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> > Suggested-by: Thomas Lendacy <thomas.lendacky@xxxxxxx> > Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> > Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx> > --- > arch/x86/boot/compressed/misc.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
