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-rw-r--r--arch/x86/kernel/pci-dma.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index df96926421be..04140e20ef1a 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -53,6 +53,14 @@ static void __init pci_swiotlb_detect(void)
if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
x86_swiotlb_enable = true;
+ /*
+ * Guest with guest memory encryption currently perform all DMA through
+ * bounce buffers as the hypervisor can't access arbitrary VM memory
+ * that is not explicitly shared with it.
+ */
+ if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
+ swiotlb_force = SWIOTLB_FORCE;
+
if (swiotlb_force == SWIOTLB_FORCE)
x86_swiotlb_enable = true;
}