Subject: [RFC PATCH 05/11] powerpc/svm: Don't release SWIOTLB buffers on secure guests

From: Thiago Jung Bauermann <[email-masked]>
Date: Fri, 24 Aug 2018 13:25:29 -0300

From: Anshuman Khandual <[email-masked]>

Even though SWIOTLB slab gets allocated and initialized on each powerpc
platform with swiotlb_init(), it gets released away again on all server
platforms because ppc_swiotlb_enable variable never gets set. Secure
guests would require SWIOTLB DMA API support for virtio bounce buffering
purpose. Hence retain the allocated buffer by setting ppc_swiotlb_enable
variable for secure guests on Ultravisor platforms.

Signed-off-by: Anshuman Khandual <[email-masked]>
Signed-off-by: Thiago Jung Bauermann <[email-masked]>
---
 arch/powerpc/kernel/svm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kernel/svm.c b/arch/powerpc/kernel/svm.c
index eab2a64d8643..891db2de8c04 100644
--- a/arch/powerpc/kernel/svm.c
+++ b/arch/powerpc/kernel/svm.c
@@ -16,6 +16,7 @@ static int __init init_svm(void)
 	if (!is_svm_platform())
 		return 0;
 
+	ppc_swiotlb_enable = 1;
 	swiotlb_update_mem_attributes();
 
 	return 0;