On 4/28/25 14:26, Ashish Kalra wrote:
From: Ashish Kalra ashish.kalra@amd.com
When the shared pages are being made private during kdump preparation there are additional checks to handle shared GHCB pages.
These additional checks include handling the case of GHCB page being contained within a huge page.
There is a bug in this additional check for GHCB page contained within a huge page which causes any shared page just below the per-cpu GHCB getting skipped from being transitioned back to private before kdump preparation which subsequently causes a 0x404 #VC exception when this shared page is accessed later while dumping guest memory during vmcore generation via kdump.
Correct the detection and handling of GHCB pages contained within a huge page.
Cc: stable@vger.kernel.org Fixes: 3074152e56c9 ("x86/sev: Convert shared memory back to private on kexec") Signed-off-by: Ashish Kalra ashish.kalra@amd.com
Reviewed-by: Tom Lendacky thomas.lendacky@amd.com
arch/x86/coco/sev/core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)