[RFC PATCH 00/12] x86/Hyper-V: Add Hyper-V Isolation VM support

[RFC PATCH 00/12] x86/Hyper-V: Add Hyper-V Isolation VM support

[Tianyu Lan]

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

Hyper-V provides two kinds of Isolation VMs. VBS(Virtualization-based
security) and AMD SEV-SNP unenlightened Isolation VMs. This patchset
is to add support for these Isolation VM support in Linux.

The memory of these vms are encrypted and host can't access guest
memory directly. Hyper-V provides new host visibility hvcall and
the guest needs to call new hvcall to mark memory visible to host
before sharing memory with host. For security, all network/storage
stack memory should not be shared with host and so there is bounce
buffer requests.

Vmbus channel ring buffer already plays bounce buffer role because
all data from/to host needs to copy from/to between the ring buffer
and IO stack memory. So mark vmbus channel ring buffer visible.

There are two exceptions - packets sent by vmbus_sendpacket_
pagebuffer() and vmbus_sendpacket_mpb_desc(). These packets
contains IO stack memory address and host will access these memory.
So add allocation bounce buffer support in vmbus for these packets.

For SNP isolation VM, guest needs to access the shared memory via
extra address space which is specified by Hyper-V CPUID HYPERV_CPUID_
ISOLATION_CONFIG. The access physical address of the shared memory
should be bounce buffer memory GPA plus with shared_gpa_boundary
reported by CPUID.

Tianyu Lan (12):
  x86/Hyper-V: Add visibility parameter for vmbus_establish_gpadl()
  x86/Hyper-V: Add new hvcall guest address host visibility support
  x86/HV: Initialize GHCB page and shared memory boundary
  HV: Add Write/Read MSR registers via ghcb
  HV: Add ghcb hvcall support for SNP VM
  HV/Vmbus: Add SNP support for VMbus channel initiate message
  hv/vmbus: Initialize VMbus ring buffer for Isolation VM
  x86/Hyper-V: Initialize bounce buffer page cache and list
  x86/Hyper-V: Add new parameter for
    vmbus_sendpacket_pagebuffer()/mpb_desc()
  HV: Add bounce buffer support for Isolation VM
  HV/Netvsc: Add Isolation VM support for netvsc driver
  HV/Storvsc: Add bounce buffer support for Storvsc

 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |  70 +++-
 arch/x86/hyperv/ivm.c              | 257 ++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  22 +
 arch/x86/include/asm/mshyperv.h    |  26 +-
 arch/x86/kernel/cpu/mshyperv.c     |   2 +
 drivers/hv/Makefile                |   2 +-
 drivers/hv/channel.c               | 103 ++++-
 drivers/hv/channel_mgmt.c          |  30 +-
 drivers/hv/connection.c            |  68 +++-
 drivers/hv/hv.c                    | 196 ++++++---
 drivers/hv/hv_bounce.c             | 619 +++++++++++++++++++++++++++++
 drivers/hv/hyperv_vmbus.h          |  42 ++
 drivers/hv/ring_buffer.c           |  83 +++-
 drivers/net/hyperv/hyperv_net.h    |   5 +
 drivers/net/hyperv/netvsc.c        | 111 +++++-
 drivers/scsi/storvsc_drv.c         |  46 ++-
 drivers/uio/uio_hv_generic.c       |  13 +-
 include/asm-generic/hyperv-tlfs.h  |   1 +
 include/asm-generic/mshyperv.h     |  24 +-
 include/linux/hyperv.h             |  46 ++-
 mm/ioremap.c                       |   1 +
 mm/vmalloc.c                       |   1 +
 23 files changed, 1614 insertions(+), 156 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c
 create mode 100644 drivers/hv/hv_bounce.c

-- 
2.25.1

[RFC PATCH 7/12] hv/vmbus: Initialize VMbus ring buffer for Isolation VM

[Tianyu Lan]

From: Tianyu Lan <Tianyu.Lan@microsoft.com>

VMbus ring buffer are shared with host and it's need to
be accessed via extra address space of Isolation VM with
SNP support. This patch is to map the ring buffer
address in extra address space via ioremap(). HV host
visibility hvcall smears data in the ring buffer and
so reset the ring buffer memory to zero after calling
visibility hvcall.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/hv/channel.c      | 10 +++++
 drivers/hv/hyperv_vmbus.h |  2 +
 drivers/hv/ring_buffer.c  | 83 +++++++++++++++++++++++++++++----------
 mm/ioremap.c              |  1 +
 mm/vmalloc.c              |  1 +
 5 files changed, 76 insertions(+), 21 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f31b669a1ddf..4c05b1488649 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -657,6 +657,16 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
 	if (err)
 		goto error_clean_ring;
 
+	err = hv_ringbuffer_post_init(&newchannel->outbound,
+				      page, send_pages);
+	if (err)
+		goto error_free_gpadl;
+
+	err = hv_ringbuffer_post_init(&newchannel->inbound,
+				      &page[send_pages], recv_pages);
+	if (err)
+		goto error_free_gpadl;
+
 	/* Create and init the channel open message */
 	open_info = kzalloc(sizeof(*open_info) +
 			   sizeof(struct vmbus_channel_open_channel),
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 0778add21a9c..d78a04ad5490 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -172,6 +172,8 @@ extern int hv_synic_cleanup(unsigned int cpu);
 /* Interface */
 
 void hv_ringbuffer_pre_init(struct vmbus_channel *channel);
+int hv_ringbuffer_post_init(struct hv_ring_buffer_info *ring_info,
+		struct page *pages, u32 page_cnt);
 
 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		       struct page *pages, u32 pagecnt);
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 35833d4d1a1d..c8b0f7b45158 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -17,6 +17,8 @@
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/prefetch.h>
+#include <linux/io.h>
+#include <asm/mshyperv.h>
 
 #include "hyperv_vmbus.h"
 
@@ -188,6 +190,44 @@ void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
 	mutex_init(&channel->outbound.ring_buffer_mutex);
 }
 
+int hv_ringbuffer_post_init(struct hv_ring_buffer_info *ring_info,
+		       struct page *pages, u32 page_cnt)
+{
+	struct vm_struct *area;
+	u64 physic_addr = page_to_pfn(pages) << PAGE_SHIFT;
+	unsigned long vaddr;
+	int err = 0;
+
+	if (!hv_isolation_type_snp())
+		return 0;
+
+	physic_addr += ms_hyperv.shared_gpa_boundary;
+	area = get_vm_area((2 * page_cnt - 1) * PAGE_SIZE, VM_IOREMAP);
+	if (!area || !area->addr)
+		return -EFAULT;
+
+	vaddr = (unsigned long)area->addr;
+	err = ioremap_page_range(vaddr, vaddr + page_cnt * PAGE_SIZE,
+			   physic_addr, PAGE_KERNEL_IO);
+	err |= ioremap_page_range(vaddr + page_cnt * PAGE_SIZE,
+				  vaddr + (2 * page_cnt - 1) * PAGE_SIZE,
+				  physic_addr + PAGE_SIZE, PAGE_KERNEL_IO);
+	if (err) {
+		vunmap((void *)vaddr);
+		return -EFAULT;
+	}
+
+	/* Clean memory after setting host visibility. */
+	memset((void *)vaddr, 0x00, page_cnt * PAGE_SIZE);
+
+	ring_info->ring_buffer = (struct hv_ring_buffer *)vaddr;
+	ring_info->ring_buffer->read_index = 0;
+	ring_info->ring_buffer->write_index = 0;
+	ring_info->ring_buffer->feature_bits.value = 1;
+
+	return 0;
+}
+
 /* Initialize the ring buffer. */
 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		       struct page *pages, u32 page_cnt)
@@ -197,33 +237,34 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 
 	BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
 
-	/*
-	 * First page holds struct hv_ring_buffer, do wraparound mapping for
-	 * the rest.
-	 */
-	pages_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(struct page *),
-				   GFP_KERNEL);
-	if (!pages_wraparound)
-		return -ENOMEM;
-
-	pages_wraparound[0] = pages;
-	for (i = 0; i < 2 * (page_cnt - 1); i++)
-		pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
+	if (!hv_isolation_type_snp()) {
+		/*
+		 * First page holds struct hv_ring_buffer, do wraparound mapping for
+		 * the rest.
+		 */
+		pages_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(struct page *),
+					   GFP_KERNEL);
+		if (!pages_wraparound)
+			return -ENOMEM;
 
-	ring_info->ring_buffer = (struct hv_ring_buffer *)
-		vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL);
+		pages_wraparound[0] = pages;
+		for (i = 0; i < 2 * (page_cnt - 1); i++)
+			pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
 
-	kfree(pages_wraparound);
+		ring_info->ring_buffer = (struct hv_ring_buffer *)
+			vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL);
 
+		kfree(pages_wraparound);
 
-	if (!ring_info->ring_buffer)
-		return -ENOMEM;
+		if (!ring_info->ring_buffer)
+			return -ENOMEM;
 
-	ring_info->ring_buffer->read_index =
-		ring_info->ring_buffer->write_index = 0;
+		ring_info->ring_buffer->read_index =
+			ring_info->ring_buffer->write_index = 0;
 
-	/* Set the feature bit for enabling flow control. */
-	ring_info->ring_buffer->feature_bits.value = 1;
+		/* Set the feature bit for enabling flow control. */
+		ring_info->ring_buffer->feature_bits.value = 1;
+	}
 
 	ring_info->ring_size = page_cnt << PAGE_SHIFT;
 	ring_info->ring_size_div10_reciprocal =
diff --git a/mm/ioremap.c b/mm/ioremap.c
index 5fa1ab41d152..d63c4ba067f9 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -248,6 +248,7 @@ int ioremap_page_range(unsigned long addr,
 
 	return err;
 }
+EXPORT_SYMBOL_GPL(ioremap_page_range);
 
 #ifdef CONFIG_GENERIC_IOREMAP
 void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e6f352bf0498..19724a8ebcb7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2131,6 +2131,7 @@ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 				  NUMA_NO_NODE, GFP_KERNEL,
 				  __builtin_return_address(0));
 }
+EXPORT_SYMBOL_GPL(get_vm_area);
 
 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
 				const void *caller)
-- 
2.25.1