net: netvsc: Add Isolation VM support for netvsc driver

In Isolation VM, all shared memory with host needs to mark visible
to host via hvcall. vmbus_establish_gpadl() has already done it for
netvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
pagebuffer() stills need to be handled. Use DMA API to map/umap
these memory during sending/receiving packet and Hyper-V swiotlb
bounce buffer dma address will be returned. The swiotlb bounce buffer
has been masked to be visible to host during boot up.

rx/tx ring buffer is allocated via vzalloc() and they need to be
mapped into unencrypted address space(above vTOM) before sharing
with host and accessing. Add hv_map/unmap_memory() to map/umap rx
/tx ring buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211213071407.314309-6-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 3e2248ac328e..94e73ba129c5 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -269,6 +269,8 @@ bool hv_isolation_type_snp(void);
 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
+void *hv_map_memory(void *addr, unsigned long size);
+void hv_unmap_memory(void *addr);
 #else /* CONFIG_HYPERV */
 static inline bool hv_is_hyperv_initialized(void) { return false; }
 static inline bool hv_is_hibernation_supported(void) { return false; }