On 10/5/24 12:43 AM, Steven Price wrote:
Within a realm guest it's not possible for a device emulated by the VMM to access arbitrary guest memory. So force the use of bounce buffers to ensure that the memory the emulated devices are accessing is in memory which is explicitly shared with the host. This adds a call to swiotlb_update_mem_attributes() which calls set_memory_decrypted() to ensure the bounce buffer memory is shared with the host. For non-realm guests or hosts this is a no-op. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Co-developed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx> Signed-off-by: Steven Price <steven.price@xxxxxxx> --- v3: Simplify mem_init() by using a 'flags' variable. --- arch/arm64/kernel/rsi.c | 1 + arch/arm64/mm/init.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-)
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
