Commit 25727aae authored by Michael Kelley's avatar Michael Kelley Committed by Wei Liu
Browse files

hv_netvsc: Remove second mapping of send and recv buffers 



With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary.  Everything needed
for the transition to shared is handled by set_memory_decrypted().

As such, remove the code to create and manage the second
mapping for the pre-allocated send and recv buffers.  This mapping
is the last user of hv_map_memory()/hv_unmap_memory(), so delete
these functions as well.  Finally, hv_map_memory() is the last
user of vmap_pfn() in Hyper-V guest code, so remove the Kconfig
selection of VMAP_PFN.

Signed-off-by: default avatarMichael Kelley <mikelley@microsoft.com>
Reviewed-by: default avatarTianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-11-git-send-email-mikelley@microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent bb862397

arch/x86/hyperv/ivm.c

+0 −28
Original line number Diff line number Diff line
@@ -376,34 +376,6 @@ void __init hv_vtom_init(void) 


#endif /* CONFIG_AMD_MEM_ENCRYPT */



/*

 * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.

 */

void *hv_map_memory(void *addr, unsigned long size)

{

	unsigned long *pfns = kcalloc(size / PAGE_SIZE,

				      sizeof(unsigned long), GFP_KERNEL);

	void *vaddr;

	int i;



	if (!pfns)

		return NULL;



	for (i = 0; i < size / PAGE_SIZE; i++)

		pfns[i] = vmalloc_to_pfn(addr + i * PAGE_SIZE) +

			(ms_hyperv.shared_gpa_boundary >> PAGE_SHIFT);



	vaddr = vmap_pfn(pfns, size / PAGE_SIZE, pgprot_decrypted(PAGE_KERNEL));

	kfree(pfns);



	return vaddr;

}



void hv_unmap_memory(void *addr)

{

	vunmap(addr);

}



enum hv_isolation_type hv_get_isolation_type(void)

{

	if (!(ms_hyperv.priv_high & HV_ISOLATION))

drivers/hv/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ config HYPERV 
		|| (ACPI && ARM64 && !CPU_BIG_ENDIAN)

	select PARAVIRT

	select X86_HV_CALLBACK_VECTOR if X86

	select VMAP_PFN

	select OF_EARLY_FLATTREE if OF

	help

	  Select this option to run Linux as a Hyper-V client operating

drivers/hv/hv_common.c

+0 −11
Original line number Diff line number Diff line
@@ -311,14 +311,3 @@ u64 __weak hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_s 
	return HV_STATUS_INVALID_PARAMETER;

}

EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
 


void __weak *hv_map_memory(void *addr, unsigned long size)

{

	return NULL;

}

EXPORT_SYMBOL_GPL(hv_map_memory);



void __weak hv_unmap_memory(void *addr)

{

}

EXPORT_SYMBOL_GPL(hv_unmap_memory);

drivers/net/hyperv/hyperv_net.h

+0 −2
Original line number Diff line number Diff line
@@ -1139,7 +1139,6 @@ struct netvsc_device { 


	/* Receive buffer allocated by us but manages by NetVSP */

	void *recv_buf;

	void *recv_original_buf;

	u32 recv_buf_size; /* allocated bytes */

	struct vmbus_gpadl recv_buf_gpadl_handle;

	u32 recv_section_cnt;
@@ -1148,7 +1147,6 @@ struct netvsc_device { 


	/* Send buffer allocated by us */

	void *send_buf;

	void *send_original_buf;

	u32 send_buf_size;

	struct vmbus_gpadl send_buf_gpadl_handle;

	u32 send_section_cnt;

drivers/net/hyperv/netvsc.c

+2 −46
Original line number Diff line number Diff line
@@ -154,17 +154,8 @@ static void free_netvsc_device(struct rcu_head *head) 
	int i;



	kfree(nvdev->extension);



	if (nvdev->recv_original_buf)

		vfree(nvdev->recv_original_buf);

	else

	vfree(nvdev->recv_buf);



	if (nvdev->send_original_buf)

		vfree(nvdev->send_original_buf);

	else

	vfree(nvdev->send_buf);



	bitmap_free(nvdev->send_section_map);



	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
@@ -347,7 +338,6 @@ static int netvsc_init_buf(struct hv_device *device, 
	struct nvsp_message *init_packet;

	unsigned int buf_size;

	int i, ret = 0;

	void *vaddr;



	/* Get receive buffer area. */

	buf_size = device_info->recv_sections * device_info->recv_section_size;
@@ -383,17 +373,6 @@ static int netvsc_init_buf(struct hv_device *device, 
		goto cleanup;

	}



	if (hv_isolation_type_snp()) {

		vaddr = hv_map_memory(net_device->recv_buf, buf_size);

		if (!vaddr) {

			ret = -ENOMEM;

			goto cleanup;

		}



		net_device->recv_original_buf = net_device->recv_buf;

		net_device->recv_buf = vaddr;

	}



	/* Notify the NetVsp of the gpadl handle */

	init_packet = &net_device->channel_init_pkt;

	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -497,17 +476,6 @@ static int netvsc_init_buf(struct hv_device *device, 
		goto cleanup;

	}



	if (hv_isolation_type_snp()) {

		vaddr = hv_map_memory(net_device->send_buf, buf_size);

		if (!vaddr) {

			ret = -ENOMEM;

			goto cleanup;

		}



		net_device->send_original_buf = net_device->send_buf;

		net_device->send_buf = vaddr;

	}



	/* Notify the NetVsp of the gpadl handle */

	init_packet = &net_device->channel_init_pkt;

	memset(init_packet, 0, sizeof(struct nvsp_message));
@@ -762,12 +730,6 @@ void netvsc_device_remove(struct hv_device *device) 
		netvsc_teardown_send_gpadl(device, net_device, ndev);

	}



	if (net_device->recv_original_buf)

		hv_unmap_memory(net_device->recv_buf);



	if (net_device->send_original_buf)

		hv_unmap_memory(net_device->send_buf);



	/* Release all resources */

	free_netvsc_device_rcu(net_device);

}
@@ -1844,12 +1806,6 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device, 
	netif_napi_del(&net_device->chan_table[0].napi);



cleanup2:

	if (net_device->recv_original_buf)

		hv_unmap_memory(net_device->recv_buf);



	if (net_device->send_original_buf)

		hv_unmap_memory(net_device->send_buf);



	free_netvsc_device(&net_device->rcu);



	return ERR_PTR(ret);