[kvm-devel] [PATCH 5/8] KVM: PVDMA: Update dma_alloc_coherent to make it paravirt-aware

[Amit S. <ami...@qu...>]

Of all the DMA calls, only dma_alloc_coherent might not actually
call dma_ops->alloc_coherent. We make sure that gets called
if the device that's being worked on is a PV device

Signed-off-by: Amit Shah <ami...@qu...>
---
 arch/x86/kernel/pci-dma_64.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index aa805b1..d4b1713 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -11,6 +11,7 @@
 #include <asm/io.h>
 #include <asm/gart.h>
 #include <asm/calgary.h>
+#include <linux/kvm_para.h>
 
 int iommu_merge __read_mostly = 1;
 EXPORT_SYMBOL(iommu_merge);
@@ -134,6 +135,18 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		memset(memory, 0, size);
 		if (!mmu) {
 			*dma_handle = virt_to_bus(memory);
+			if (unlikely(dma_ops->is_pv_device)
+			    && unlikely(dma_ops->is_pv_device(dev, dev->bus_id))) {
+				void *r;
+				r = dma_ops->alloc_coherent(dev, size,
+							    dma_handle,
+							    gfp);
+				if (r == NULL) {
+					free_pages((unsigned long)memory,
+						   get_order(size));
+					memory = NULL;
+				}
+			}
 			return memory;
 		}
 	}
-- 
1.5.3