linuxmsm/laptops-kernel
0
0
Fork 0
mirror of https://github.com/linux-msm/laptops-kernel.git synced 2026-08-13 14:19:53 -07:00
Code Issues Packages Projects Releases Wiki Activity

virt: vmgenid: remap memory as decrypted

Browse Source 
It was found that AWS SEV-SNP enabled instances are not able to boot with
commit 81256a50aa ("x86/mm: Make memremap(MEMREMAP_WB) map memory as
encrypted by default") applied and the reason seems to be the vmgenid
device which requires unencrypted writeable memory.

A similar problem was previously fixed in DRM with commit
7dfede7d7e ("drm/vmwgfx: Fix guests running with TDX/SEV").

Note, trusting vmgenid device in a Confidential VM is questionable: the
malicious host may intentionally avoid notifying the guest when a copy is
created.

Fixes: 81256a50aa ("x86/mm: Make memremap(MEMREMAP_WB) map memory as encrypted by default")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org # 6.15+
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Vitaly Kuznetsov
2025-12-22 16:18:54 +01:00
committed by Jason A. Donenfeld
parent 3f9f025213
commit bb9ff576fd
1 changed files with 2 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/virt/vmgenid.c
+2 -1
View File
@@ -75,7 +75,8 @@ static int vmgenid_add_acpi(struct device *dev, struct vmgenid_state *state)
phys_addr = (obj->package.elements[0].integer.value << 0) |
(obj->package.elements[1].integer.value << 32);
virt_addr = devm_memremap(&device->dev, phys_addr, VMGENID_SIZE, MEMREMAP_WB);
virt_addr = devm_memremap(&device->dev, phys_addr, VMGENID_SIZE,
MEMREMAP_WB | MEMREMAP_DEC);
if (IS_ERR(virt_addr)) {
ret = PTR_ERR(virt_addr);
goto out;