[Resend RFC PATCH V4 00/13] x86/Hyper-V: Add Hyper-V Isolation VM support

[Resend RFC PATCH V4 00/13] 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.

Change since v3:
       - Add interface set_memory_decrypted_map() to decrypt memory and
         map bounce buffer in extra address space 
       - Remove swiotlb remap function and store the remap address
         returned by set_memory_decrypted_map() in swiotlb mem data structure.
       - Introduce hv_set_mem_enc() to make code more readable in the __set_memory_enc_dec().

Change since v2:
       - Remove not UIO driver in Isolation VM patch
       - Use vmap_pfn() to replace ioremap_page_range function in
       order to avoid exposing symbol ioremap_page_range() and
       ioremap_page_range()
       - Call hv set mem host visibility hvcall in set_memory_encrypted/decrypted()
       - Enable swiotlb force mode instead of adding Hyper-V dma map/unmap hook
       - Fix code style

Tianyu Lan (13):
  x86/HV: Initialize GHCB page in Isolation VM
  x86/HV: Initialize shared memory boundary in the Isolation VM.
  x86/HV: Add new hvcall guest address host visibility support
  HV: Mark vmbus ring buffer visible to host in Isolation VM
  HV: Add Write/Read MSR registers via ghcb page
  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/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM
  HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM
  HV/Netvsc: Add Isolation VM support for netvsc driver
  HV/Storvsc: Add Isolation VM support for storvsc driver
  x86/HV: Not set memory decrypted/encrypted during kexec alloc/free
    page in IVM

 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |  25 +--
 arch/x86/hyperv/ivm.c              | 299 +++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  18 ++
 arch/x86/include/asm/mshyperv.h    |  84 +++++++-
 arch/x86/include/asm/set_memory.h  |   2 +
 arch/x86/include/asm/sev-es.h      |   4 +
 arch/x86/kernel/cpu/mshyperv.c     |   5 +
 arch/x86/kernel/machine_kexec_64.c |   5 +-
 arch/x86/kernel/sev-es-shared.c    |  21 +-
 arch/x86/mm/pat/set_memory.c       |  34 +++-
 arch/x86/xen/pci-swiotlb-xen.c     |   3 +-
 drivers/hv/Kconfig                 |   1 +
 drivers/hv/channel.c               |  48 ++++-
 drivers/hv/connection.c            |  71 ++++++-
 drivers/hv/hv.c                    | 129 +++++++++----
 drivers/hv/hyperv_vmbus.h          |   3 +
 drivers/hv/ring_buffer.c           |  84 ++++++--
 drivers/hv/vmbus_drv.c             |   3 +
 drivers/iommu/hyperv-iommu.c       |  62 ++++++
 drivers/net/hyperv/hyperv_net.h    |   6 +
 drivers/net/hyperv/netvsc.c        | 144 +++++++++++++-
 drivers/net/hyperv/rndis_filter.c  |   2 +
 drivers/scsi/storvsc_drv.c         |  68 ++++++-
 include/asm-generic/hyperv-tlfs.h  |   1 +
 include/asm-generic/mshyperv.h     |  53 ++++-
 include/linux/hyperv.h             |  16 ++
 include/linux/swiotlb.h            |   4 +
 kernel/dma/swiotlb.c               |  11 +-
 29 files changed, 1097 insertions(+), 111 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

-- 
2.25.1

[Resend RFC PATCH V4 01/13] x86/HV: Initialize GHCB page in Isolation VM

[Tianyu Lan]

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

Hyper-V exposes GHCB page via SEV ES GHCB MSR for SNP guest
to communicate with hypervisor. Map GHCB page for all
cpus to read/write MSR register and submit hvcall request
via GHCB.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/hv_init.c       | 64 ++++++++++++++++++++++++++++++---
 arch/x86/include/asm/mshyperv.h |  2 ++
 include/asm-generic/mshyperv.h  |  2 ++
 3 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index b756b2866deb..e058f72eeee5 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
 #include <linux/kexec.h>
 #include <linux/version.h>
 #include <linux/vmalloc.h>
+#include <linux/io.h>
 #include <linux/mm.h>
 #include <linux/hyperv.h>
 #include <linux/slab.h>
@@ -54,6 +55,26 @@ EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
 u32 hv_max_vp_index;
 EXPORT_SYMBOL_GPL(hv_max_vp_index);
 
+static int hyperv_init_ghcb(void)
+{
+	u64 ghcb_gpa;
+	void *ghcb_va;
+	void **ghcb_base;
+
+	if (!ms_hyperv.ghcb_base)
+		return -EINVAL;
+
+	rdmsrl(MSR_AMD64_SEV_ES_GHCB, ghcb_gpa);
+	ghcb_va = memremap(ghcb_gpa, HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+	if (!ghcb_va)
+		return -ENOMEM;
+
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	*ghcb_base = ghcb_va;
+
+	return 0;
+}
+
 static int hv_cpu_init(unsigned int cpu)
 {
 	u64 msr_vp_index;
@@ -106,6 +127,8 @@ static int hv_cpu_init(unsigned int cpu)
 		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, val);
 	}
 
+	hyperv_init_ghcb();
+
 	return 0;
 }
 
@@ -201,6 +224,7 @@ static int hv_cpu_die(unsigned int cpu)
 	unsigned long flags;
 	void **input_arg;
 	void *pg;
+	void **ghcb_va = NULL;
 
 	local_irq_save(flags);
 	input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
@@ -214,6 +238,13 @@ static int hv_cpu_die(unsigned int cpu)
 		*output_arg = NULL;
 	}
 
+	if (ms_hyperv.ghcb_base) {
+		ghcb_va = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+		if (*ghcb_va)
+			memunmap(*ghcb_va);
+		*ghcb_va = NULL;
+	}
+
 	local_irq_restore(flags);
 
 	free_pages((unsigned long)pg, hv_root_partition ? 1 : 0);
@@ -410,9 +441,22 @@ void __init hyperv_init(void)
 			VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
 			VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
 			__builtin_return_address(0));
-	if (hv_hypercall_pg == NULL) {
-		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
-		goto remove_cpuhp_state;
+	if (hv_hypercall_pg == NULL)
+		goto clean_guest_os_id;
+
+	if (hv_isolation_type_snp()) {
+		ms_hyperv.ghcb_base = alloc_percpu(void *);
+		if (!ms_hyperv.ghcb_base)
+			goto clean_guest_os_id;
+
+		if (hyperv_init_ghcb()) {
+			free_percpu(ms_hyperv.ghcb_base);
+			ms_hyperv.ghcb_base = NULL;
+			goto clean_guest_os_id;
+		}
+
+		/* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
+		hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, guest_id);
 	}
 
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
@@ -473,7 +517,8 @@ void __init hyperv_init(void)
 	hv_query_ext_cap(0);
 	return;
 
-remove_cpuhp_state:
+clean_guest_os_id:
+	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 	cpuhp_remove_state(cpuhp);
 free_vp_assist_page:
 	kfree(hv_vp_assist_page);
@@ -502,6 +547,9 @@ void hyperv_cleanup(void)
 	 */
 	hv_hypercall_pg = NULL;
 
+	if (ms_hyperv.ghcb_base)
+		free_percpu(ms_hyperv.ghcb_base);
+
 	/* Reset the hypercall page */
 	hypercall_msr.as_uint64 = 0;
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
@@ -586,6 +634,14 @@ bool hv_is_isolation_supported(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
 
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+bool hv_isolation_type_snp(void)
+{
+	return static_branch_unlikely(&isolation_type_snp);
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
+
 /* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */
 bool hv_query_ext_cap(u64 cap_query)
 {
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 67ff0d637e55..aeacca7c4da8 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -11,6 +11,8 @@
 #include <asm/paravirt.h>
 #include <asm/mshyperv.h>
 
+DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
+
 typedef int (*hyperv_fill_flush_list_func)(
 		struct hv_guest_mapping_flush_list *flush,
 		void *data);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 9a000ba2bb75..3ae56a29594f 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -35,6 +35,7 @@ struct ms_hyperv_info {
 	u32 max_lp_index;
 	u32 isolation_config_a;
 	u32 isolation_config_b;
+	void  __percpu **ghcb_base;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
@@ -224,6 +225,7 @@ bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);
 enum hv_isolation_type hv_get_isolation_type(void);
 bool hv_is_isolation_supported(void);
+bool hv_isolation_type_snp(void);
 void hyperv_cleanup(void);
 bool hv_query_ext_cap(u64 cap_query);
 #else /* CONFIG_HYPERV */
-- 
2.25.1

[Resend RFC PATCH V4 02/13] x86/HV: Initialize shared memory boundary in the Isolation VM.

[Tianyu Lan]

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

Hyper-V exposes shared memory boundary via cpuid
HYPERV_CPUID_ISOLATION_CONFIG and store it in the
shared_gpa_boundary of ms_hyperv struct. This prepares
to share memory with host for SNP guest.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/kernel/cpu/mshyperv.c |  2 ++
 include/asm-generic/mshyperv.h | 12 +++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 10b2a8c10cb6..8aed689db621 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -334,6 +334,8 @@ static void __init ms_hyperv_init_platform(void)
 	if (ms_hyperv.priv_high & HV_ISOLATION) {
 		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
 		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.shared_gpa_boundary =
+			(u64)1 << ms_hyperv.shared_gpa_boundary_bits;
 
 		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
 			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 3ae56a29594f..2914e27b0429 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -34,8 +34,18 @@ struct ms_hyperv_info {
 	u32 max_vp_index;
 	u32 max_lp_index;
 	u32 isolation_config_a;
-	u32 isolation_config_b;
+	union {
+		u32 isolation_config_b;
+		struct {
+			u32 cvm_type : 4;
+			u32 Reserved11 : 1;
+			u32 shared_gpa_boundary_active : 1;
+			u32 shared_gpa_boundary_bits : 6;
+			u32 Reserved12 : 20;
+		};
+	};
 	void  __percpu **ghcb_base;
+	u64 shared_gpa_boundary;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
-- 
2.25.1

[Resend RFC PATCH V4 03/13] x86/HV: Add new hvcall guest address host visibility support

[Tianyu Lan]

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

Add new hvcall guest address host visibility support to mark
memory visible to host. Call it inside set_memory_decrypted
/encrypted().

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/ivm.c              | 112 +++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  18 +++++
 arch/x86/include/asm/mshyperv.h    |   3 +-
 arch/x86/mm/pat/set_memory.c       |   6 +-
 include/asm-generic/hyperv-tlfs.h  |   1 +
 6 files changed, 139 insertions(+), 3 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
index 48e2c51464e8..5d2de10809ae 100644
--- a/arch/x86/hyperv/Makefile
+++ b/arch/x86/hyperv/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-y			:= hv_init.o mmu.o nested.o irqdomain.o
+obj-y			:= hv_init.o mmu.o nested.o irqdomain.o ivm.o
 obj-$(CONFIG_X86_64)	+= hv_apic.o hv_proc.o
 
 ifdef CONFIG_X86_64
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
new file mode 100644
index 000000000000..24a58795abd8
--- /dev/null
+++ b/arch/x86/hyperv/ivm.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hyper-V Isolation VM interface with paravisor and hypervisor
+ *
+ * Author:
+ *  Tianyu Lan <Tianyu.Lan@microsoft.com>
+ */
+
+#include <linux/hyperv.h>
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/slab.h>
+#include <asm/io.h>
+#include <asm/mshyperv.h>
+
+/*
+ * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
+ *
+ * In Isolation VM, all guest memory is encripted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host.
+ */
+int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility)
+{
+	struct hv_gpa_range_for_visibility **input_pcpu, *input;
+	u16 pages_processed;
+	u64 hv_status;
+	unsigned long flags;
+
+	/* no-op if partition isolation is not enabled */
+	if (!hv_is_isolation_supported())
+		return 0;
+
+	if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
+		pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
+			HV_MAX_MODIFY_GPA_REP_COUNT);
+		return -EINVAL;
+	}
+
+	local_irq_save(flags);
+	input_pcpu = (struct hv_gpa_range_for_visibility **)
+			this_cpu_ptr(hyperv_pcpu_input_arg);
+	input = *input_pcpu;
+	if (unlikely(!input)) {
+		local_irq_restore(flags);
+		return -EINVAL;
+	}
+
+	input->partition_id = HV_PARTITION_ID_SELF;
+	input->host_visibility = visibility;
+	input->reserved0 = 0;
+	input->reserved1 = 0;
+	memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
+	hv_status = hv_do_rep_hypercall(
+			HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
+			0, input, &pages_processed);
+	local_irq_restore(flags);
+
+	if (!(hv_status & HV_HYPERCALL_RESULT_MASK))
+		return 0;
+
+	return hv_status & HV_HYPERCALL_RESULT_MASK;
+}
+EXPORT_SYMBOL(hv_mark_gpa_visibility);
+
+/*
+ * hv_set_mem_host_visibility - Set specified memory visible to host.
+ *
+ * In Isolation VM, all guest memory is encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host. This function works as wrap of hv_mark_gpa_visibility()
+ * with memory base and size.
+ */
+static int hv_set_mem_host_visibility(void *kbuffer, size_t size, u32 visibility)
+{
+	int pagecount = size >> HV_HYP_PAGE_SHIFT;
+	u64 *pfn_array;
+	int ret = 0;
+	int i, pfn;
+
+	if (!hv_is_isolation_supported() || !ms_hyperv.ghcb_base)
+		return 0;
+
+	pfn_array = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+	if (!pfn_array)
+		return -ENOMEM;
+
+	for (i = 0, pfn = 0; i < pagecount; i++) {
+		pfn_array[pfn] = virt_to_hvpfn(kbuffer + i * HV_HYP_PAGE_SIZE);
+		pfn++;
+
+		if (pfn == HV_MAX_MODIFY_GPA_REP_COUNT || i == pagecount - 1) {
+			ret |= hv_mark_gpa_visibility(pfn, pfn_array, visibility);
+			pfn = 0;
+
+			if (ret)
+				goto err_free_pfn_array;
+		}
+	}
+
+ err_free_pfn_array:
+	kfree(pfn_array);
+	return ret;
+}
+
+int hv_set_mem_enc(unsigned long addr, int numpages, bool enc)
+{
+	return hv_set_mem_host_visibility((void *)addr,
+			numpages * HV_HYP_PAGE_SIZE,
+			enc ? VMBUS_PAGE_NOT_VISIBLE
+			: VMBUS_PAGE_VISIBLE_READ_WRITE);
+}
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 606f5cc579b2..68826fbf92ca 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -262,6 +262,11 @@ enum hv_isolation_type {
 #define HV_X64_MSR_TIME_REF_COUNT	HV_REGISTER_TIME_REF_COUNT
 #define HV_X64_MSR_REFERENCE_TSC	HV_REGISTER_REFERENCE_TSC
 
+/* Hyper-V GPA map flags */
+#define	VMBUS_PAGE_NOT_VISIBLE		0
+#define	VMBUS_PAGE_VISIBLE_READ_ONLY	1
+#define	VMBUS_PAGE_VISIBLE_READ_WRITE	3
+
 /*
  * Declare the MSR used to setup pages used to communicate with the hypervisor.
  */
@@ -561,4 +566,17 @@ enum hv_interrupt_type {
 
 #include <asm-generic/hyperv-tlfs.h>
 
+/* All input parameters should be in single page. */
+#define HV_MAX_MODIFY_GPA_REP_COUNT		\
+	((PAGE_SIZE / sizeof(u64)) - 2)
+
+/* HvCallModifySparseGpaPageHostVisibility hypercall */
+struct hv_gpa_range_for_visibility {
+	u64 partition_id;
+	u32 host_visibility:2;
+	u32 reserved0:30;
+	u32 reserved1;
+	u64 gpa_page_list[HV_MAX_MODIFY_GPA_REP_COUNT];
+} __packed;
+
 #endif
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index aeacca7c4da8..2172493dc881 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -194,7 +194,8 @@ struct irq_domain *hv_create_pci_msi_domain(void);
 int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 		struct hv_interrupt_entry *entry);
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
-
+int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility);
+int hv_set_mem_enc(unsigned long addr, int numpages, bool enc);
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 156cd235659f..6cc83c57383d 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -29,6 +29,8 @@
 #include <asm/proto.h>
 #include <asm/memtype.h>
 #include <asm/set_memory.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
 
 #include "../mm_internal.h"
 
@@ -1986,7 +1988,9 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	int ret;
 
 	/* Nothing to do if memory encryption is not active */
-	if (!mem_encrypt_active())
+	if (hv_is_isolation_supported())
+		return hv_set_mem_enc(addr, numpages, enc);
+	else if (!mem_encrypt_active())
 		return 0;
 
 	/* Should not be working on unaligned addresses */
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 515c3fb06ab3..8a0219255545 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -158,6 +158,7 @@ struct ms_hyperv_tsc_page {
 #define HVCALL_RETARGET_INTERRUPT		0x007e
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
 #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
+#define HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY 0x00db
 
 /* Extended hypercalls */
 #define HV_EXT_CALL_QUERY_CAPABILITIES		0x8001
-- 
2.25.1

[Resend RFC PATCH V4 04/13] HV: Mark vmbus ring buffer visible to host in Isolation VM

[Tianyu Lan]

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

Mark vmbus ring buffer visible with set_memory_decrypted() when
establish gpadl handle.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/hv/channel.c   | 38 ++++++++++++++++++++++++++++++++++++--
 include/linux/hyperv.h | 10 ++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f3761c73b074..01048bb07082 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -17,6 +17,7 @@
 #include <linux/hyperv.h>
 #include <linux/uio.h>
 #include <linux/interrupt.h>
+#include <linux/set_memory.h>
 #include <asm/page.h>
 #include <asm/mshyperv.h>
 
@@ -465,7 +466,7 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	struct list_head *curr;
 	u32 next_gpadl_handle;
 	unsigned long flags;
-	int ret = 0;
+	int ret = 0, index;
 
 	next_gpadl_handle =
 		(atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
@@ -474,6 +475,13 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	if (ret)
 		return ret;
 
+	ret = set_memory_decrypted((unsigned long)kbuffer,
+				   HVPFN_UP(size));
+	if (ret) {
+		pr_warn("Failed to set host visibility.\n");
+		return ret;
+	}
+
 	init_completion(&msginfo->waitevent);
 	msginfo->waiting_channel = channel;
 
@@ -539,6 +547,15 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	/* At this point, we received the gpadl created msg */
 	*gpadl_handle = gpadlmsg->gpadl;
 
+	if (type == HV_GPADL_BUFFER)
+		index = 0;
+	else
+		index = channel->gpadl_range[1].gpadlhandle ? 2 : 1;
+
+	channel->gpadl_range[index].size = size;
+	channel->gpadl_range[index].buffer = kbuffer;
+	channel->gpadl_range[index].gpadlhandle = *gpadl_handle;
+
 cleanup:
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&msginfo->msglistentry);
@@ -549,6 +566,11 @@ static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
 	}
 
 	kfree(msginfo);
+
+	if (ret)
+		set_memory_encrypted((unsigned long)kbuffer,
+				     HVPFN_UP(size));
+
 	return ret;
 }
 
@@ -811,7 +833,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 	struct vmbus_channel_gpadl_teardown *msg;
 	struct vmbus_channel_msginfo *info;
 	unsigned long flags;
-	int ret;
+	int ret, i;
 
 	info = kzalloc(sizeof(*info) +
 		       sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
@@ -859,6 +881,18 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
 	kfree(info);
+
+	/* Find gpadl buffer virtual address and size. */
+	for (i = 0; i < VMBUS_GPADL_RANGE_COUNT; i++)
+		if (channel->gpadl_range[i].gpadlhandle == gpadl_handle)
+			break;
+
+	if (set_memory_encrypted((unsigned long)channel->gpadl_range[i].buffer,
+			HVPFN_UP(channel->gpadl_range[i].size)))
+		pr_warn("Fail to set mem host visibility.\n");
+
+	channel->gpadl_range[i].gpadlhandle = 0;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 2e859d2f9609..06eccaba10c5 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -809,6 +809,14 @@ struct vmbus_device {
 
 #define VMBUS_DEFAULT_MAX_PKT_SIZE 4096
 
+struct vmbus_gpadl_range {
+	u32 gpadlhandle;
+	u32 size;
+	void *buffer;
+};
+
+#define VMBUS_GPADL_RANGE_COUNT		3
+
 struct vmbus_channel {
 	struct list_head listentry;
 
@@ -829,6 +837,8 @@ struct vmbus_channel {
 	struct completion rescind_event;
 
 	u32 ringbuffer_gpadlhandle;
+	/* GPADL_RING and Send/Receive GPADL_BUFFER. */
+	struct vmbus_gpadl_range gpadl_range[VMBUS_GPADL_RANGE_COUNT];
 
 	/* Allocated memory for ring buffer */
 	struct page *ringbuffer_page;
-- 
2.25.1

[Resend RFC PATCH V4 05/13] HV: Add Write/Read MSR registers via ghcb page

[Tianyu Lan]

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

Hyper-V provides GHCB protocol to write Synthetic Interrupt
Controller MSR registers in Isolation VM with AMD SEV SNP
and these registers are emulated by hypervisor directly.
Hyper-V requires to write SINTx MSR registers twice. First
writes MSR via GHCB page to communicate with hypervisor
and then writes wrmsr instruction to talk with paravisor
which runs in VMPL0. Guest OS ID MSR also needs to be set
via GHCB.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/hv_init.c       |  25 +------
 arch/x86/hyperv/ivm.c           | 115 ++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h |  78 +++++++++++++++++++-
 arch/x86/include/asm/sev-es.h   |   4 ++
 arch/x86/kernel/cpu/mshyperv.c  |   3 +
 arch/x86/kernel/sev-es-shared.c |  21 ++++--
 drivers/hv/hv.c                 | 121 ++++++++++++++++++++++----------
 include/asm-generic/mshyperv.h  |  12 +++-
 8 files changed, 308 insertions(+), 71 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index e058f72eeee5..97d1c774cfce 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -445,7 +445,7 @@ void __init hyperv_init(void)
 		goto clean_guest_os_id;
 
 	if (hv_isolation_type_snp()) {
-		ms_hyperv.ghcb_base = alloc_percpu(void *);
+		ms_hyperv.ghcb_base = alloc_percpu(union hv_ghcb __percpu *);
 		if (!ms_hyperv.ghcb_base)
 			goto clean_guest_os_id;
 
@@ -539,6 +539,7 @@ void hyperv_cleanup(void)
 
 	/* Reset our OS id */
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+	hv_ghcb_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
 
 	/*
 	 * Reset hypercall page reference before reset the page,
@@ -620,28 +621,6 @@ bool hv_is_hibernation_supported(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
 
-enum hv_isolation_type hv_get_isolation_type(void)
-{
-	if (!(ms_hyperv.priv_high & HV_ISOLATION))
-		return HV_ISOLATION_TYPE_NONE;
-	return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
-}
-EXPORT_SYMBOL_GPL(hv_get_isolation_type);
-
-bool hv_is_isolation_supported(void)
-{
-	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
-}
-EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
-
-DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
-
-bool hv_isolation_type_snp(void)
-{
-	return static_branch_unlikely(&isolation_type_snp);
-}
-EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
-
 /* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */
 bool hv_query_ext_cap(u64 cap_query)
 {
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 24a58795abd8..c7b54631ca0d 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -6,6 +6,8 @@
  *  Tianyu Lan <Tianyu.Lan@microsoft.com>
  */
 
+#include <linux/types.h>
+#include <linux/bitfield.h>
 #include <linux/hyperv.h>
 #include <linux/types.h>
 #include <linux/bitfield.h>
@@ -13,6 +15,119 @@
 #include <asm/io.h>
 #include <asm/mshyperv.h>
 
+void hv_ghcb_msr_write(u64 msr, u64 value)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+
+	if (!ms_hyperv.ghcb_base)
+		return;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	memset(hv_ghcb, 0x00, HV_HYP_PAGE_SIZE);
+
+	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+	ghcb_set_rax(&hv_ghcb->ghcb, lower_32_bits(value));
+	ghcb_set_rdx(&hv_ghcb->ghcb, value >> 32);
+
+	if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, NULL, SVM_EXIT_MSR, 1, 0))
+		pr_warn("Fail to write msr via ghcb %llx.\n", msr);
+
+	local_irq_restore(flags);
+}
+
+void hv_ghcb_msr_read(u64 msr, u64 *value)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+
+	if (!ms_hyperv.ghcb_base)
+		return;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	memset(hv_ghcb, 0x00, HV_HYP_PAGE_SIZE);
+
+	ghcb_set_rcx(&hv_ghcb->ghcb, msr);
+	if (sev_es_ghcb_hv_call(&hv_ghcb->ghcb, NULL, SVM_EXIT_MSR, 0, 0))
+		pr_warn("Fail to read msr via ghcb %llx.\n", msr);
+	else
+		*value = (u64)lower_32_bits(hv_ghcb->ghcb.save.rax)
+			| ((u64)lower_32_bits(hv_ghcb->ghcb.save.rdx) << 32);
+	local_irq_restore(flags);
+}
+
+void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value)
+{
+	hv_ghcb_msr_read(msr, value);
+}
+EXPORT_SYMBOL_GPL(hv_sint_rdmsrl_ghcb);
+
+void hv_sint_wrmsrl_ghcb(u64 msr, u64 value)
+{
+	hv_ghcb_msr_write(msr, value);
+
+	/* Write proxy bit vua wrmsrl instruction. */
+	if (msr >= HV_X64_MSR_SINT0 && msr <= HV_X64_MSR_SINT15)
+		wrmsrl(msr, value | 1 << 20);
+}
+EXPORT_SYMBOL_GPL(hv_sint_wrmsrl_ghcb);
+
+void hv_signal_eom_ghcb(void)
+{
+	hv_sint_wrmsrl_ghcb(HV_X64_MSR_EOM, 0);
+}
+EXPORT_SYMBOL_GPL(hv_signal_eom_ghcb);
+
+enum hv_isolation_type hv_get_isolation_type(void)
+{
+	if (!(ms_hyperv.priv_high & HV_ISOLATION))
+		return HV_ISOLATION_TYPE_NONE;
+	return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b);
+}
+EXPORT_SYMBOL_GPL(hv_get_isolation_type);
+
+/*
+ * hv_is_isolation_supported - Check system runs in the Hyper-V
+ * isolation VM.
+ */
+bool hv_is_isolation_supported(void)
+{
+	return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
+}
+EXPORT_SYMBOL_GPL(hv_is_isolation_supported);
+
+DEFINE_STATIC_KEY_FALSE(isolation_type_snp);
+
+/*
+ * hv_isolation_type_snp - Check system runs in the AMD SEV-SNP based
+ * isolation VM.
+ */
+bool hv_isolation_type_snp(void)
+{
+	return static_branch_unlikely(&isolation_type_snp);
+}
+EXPORT_SYMBOL_GPL(hv_isolation_type_snp);
+
 /*
  * hv_mark_gpa_visibility - Set pages visible to host via hvcall.
  *
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 2172493dc881..f9cc3753040a 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -30,6 +30,63 @@ static inline u64 hv_get_register(unsigned int reg)
 	return value;
 }
 
+#define hv_get_sint_reg(val, reg) {		\
+	if (hv_isolation_type_snp())		\
+		hv_get_##reg##_ghcb(&val);	\
+	else					\
+		rdmsrl(HV_X64_MSR_##reg, val);	\
+	}
+
+#define hv_set_sint_reg(val, reg) {		\
+	if (hv_isolation_type_snp())		\
+		hv_set_##reg##_ghcb(val);	\
+	else					\
+		wrmsrl(HV_X64_MSR_##reg, val);	\
+	}
+
+
+#define hv_get_simp(val) hv_get_sint_reg(val, SIMP)
+#define hv_get_siefp(val) hv_get_sint_reg(val, SIEFP)
+
+#define hv_set_simp(val) hv_set_sint_reg(val, SIMP)
+#define hv_set_siefp(val) hv_set_sint_reg(val, SIEFP)
+
+#define hv_get_synic_state(val) {			\
+	if (hv_isolation_type_snp())			\
+		hv_get_synic_state_ghcb(&val);		\
+	else						\
+		rdmsrl(HV_X64_MSR_SCONTROL, val);	\
+	}
+#define hv_set_synic_state(val) {			\
+	if (hv_isolation_type_snp())			\
+		hv_set_synic_state_ghcb(val);		\
+	else						\
+		wrmsrl(HV_X64_MSR_SCONTROL, val);	\
+	}
+
+#define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index)
+
+#define hv_signal_eom() {			 \
+	if (hv_isolation_type_snp() &&		 \
+	    old_msg_type != HVMSG_TIMER_EXPIRED) \
+		hv_signal_eom_ghcb();		 \
+	else					 \
+		wrmsrl(HV_X64_MSR_EOM, 0);	 \
+	}
+
+#define hv_get_synint_state(int_num, val) {		\
+	if (hv_isolation_type_snp())			\
+		hv_get_synint_state_ghcb(int_num, &val);\
+	else						\
+		rdmsrl(HV_X64_MSR_SINT0 + int_num, val);\
+	}
+#define hv_set_synint_state(int_num, val) {		\
+	if (hv_isolation_type_snp())			\
+		hv_set_synint_state_ghcb(int_num, val);	\
+	else						\
+		wrmsrl(HV_X64_MSR_SINT0 + int_num, val);\
+	}
+
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_vector_handler(struct pt_regs *regs);
@@ -196,6 +253,25 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
 int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility);
 int hv_set_mem_enc(unsigned long addr, int numpages, bool enc);
+void hv_sint_wrmsrl_ghcb(u64 msr, u64 value);
+void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
+void hv_signal_eom_ghcb(void);
+void hv_ghcb_msr_write(u64 msr, u64 value);
+void hv_ghcb_msr_read(u64 msr, u64 *value);
+
+#define hv_get_synint_state_ghcb(int_num, val)			\
+	hv_sint_rdmsrl_ghcb(HV_X64_MSR_SINT0 + int_num, val)
+#define hv_set_synint_state_ghcb(int_num, val) \
+	hv_sint_wrmsrl_ghcb(HV_X64_MSR_SINT0 + int_num, val)
+
+#define hv_get_SIMP_ghcb(val) hv_sint_rdmsrl_ghcb(HV_X64_MSR_SIMP, val)
+#define hv_set_SIMP_ghcb(val) hv_sint_wrmsrl_ghcb(HV_X64_MSR_SIMP, val)
+
+#define hv_get_SIEFP_ghcb(val) hv_sint_rdmsrl_ghcb(HV_X64_MSR_SIEFP, val)
+#define hv_set_SIEFP_ghcb(val) hv_sint_wrmsrl_ghcb(HV_X64_MSR_SIEFP, val)
+
+#define hv_get_synic_state_ghcb(val) hv_sint_rdmsrl_ghcb(HV_X64_MSR_SCONTROL, val)
+#define hv_set_synic_state_ghcb(val) hv_sint_wrmsrl_ghcb(HV_X64_MSR_SCONTROL, val)
 #else /* CONFIG_HYPERV */
 static inline void hyperv_init(void) {}
 static inline void hyperv_setup_mmu_ops(void) {}
@@ -212,9 +288,9 @@ static inline int hyperv_flush_guest_mapping_range(u64 as,
 {
 	return -1;
 }
+static inline void hv_signal_eom_ghcb(void) { };
 #endif /* CONFIG_HYPERV */
 
-
 #include <asm-generic/mshyperv.h>
 
 #endif
diff --git a/arch/x86/include/asm/sev-es.h b/arch/x86/include/asm/sev-es.h
index cf1d957c7091..482a4bb92c48 100644
--- a/arch/x86/include/asm/sev-es.h
+++ b/arch/x86/include/asm/sev-es.h
@@ -103,6 +103,10 @@ static __always_inline void sev_es_nmi_complete(void)
 		__sev_es_nmi_complete();
 }
 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+				   struct es_em_ctxt *ctxt,
+				   u64 exit_code, u64 exit_info_1,
+				   u64 exit_info_2);
 #else
 static inline void sev_es_ist_enter(struct pt_regs *regs) { }
 static inline void sev_es_ist_exit(void) { }
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 8aed689db621..d9ac13230950 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -339,6 +339,9 @@ static void __init ms_hyperv_init_platform(void)
 
 		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
 			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
+
+		if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP)
+			static_branch_enable(&isolation_type_snp);
 	}
 
 	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) {
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c
index 0aa9f13efd57..b7da08c97d2c 100644
--- a/arch/x86/kernel/sev-es-shared.c
+++ b/arch/x86/kernel/sev-es-shared.c
@@ -93,10 +93,10 @@ static void vc_finish_insn(struct es_em_ctxt *ctxt)
 	ctxt->regs->ip += ctxt->insn.length;
 }
 
-static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
-					  struct es_em_ctxt *ctxt,
-					  u64 exit_code, u64 exit_info_1,
-					  u64 exit_info_2)
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+				   struct es_em_ctxt *ctxt,
+				   u64 exit_code, u64 exit_info_1,
+				   u64 exit_info_2)
 {
 	enum es_result ret;
 
@@ -108,7 +108,16 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
 	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
 	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
 
-	sev_es_wr_ghcb_msr(__pa(ghcb));
+	/*
+	 * Hyper-V runs paravisor with SEV. Ghcb page is allocated by
+	 * paravisor and not needs to be updated in the Linux guest.
+	 * Otherwise, the ghcb page's PA reported by paravisor is above
+	 * VTOM. Hyper-V use this function with NULL for ctxt point and
+	 * skip setting ghcb page in such case.
+	 */
+	if (ctxt)
+		sev_es_wr_ghcb_msr(__pa(ghcb));
+
 	VMGEXIT();
 
 	if ((ghcb->save.sw_exit_info_1 & 0xffffffff) == 1) {
@@ -119,7 +128,7 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
 		v = info & SVM_EVTINJ_VEC_MASK;
 
 		/* Check if exception information from hypervisor is sane. */
-		if ((info & SVM_EVTINJ_VALID) &&
+		if (ctxt && (info & SVM_EVTINJ_VALID) &&
 		    ((v == X86_TRAP_GP) || (v == X86_TRAP_UD)) &&
 		    ((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {
 			ctxt->fi.vector = v;
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e83507f49676..59f7173c4d9f 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -8,6 +8,7 @@
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
@@ -136,17 +137,24 @@ int hv_synic_alloc(void)
 		tasklet_init(&hv_cpu->msg_dpc,
 			     vmbus_on_msg_dpc, (unsigned long) hv_cpu);
 
-		hv_cpu->synic_message_page =
-			(void *)get_zeroed_page(GFP_ATOMIC);
-		if (hv_cpu->synic_message_page == NULL) {
-			pr_err("Unable to allocate SYNIC message page\n");
-			goto err;
-		}
+		/*
+		 * Synic message and event pages are allocated by paravisor.
+		 * Skip these pages allocation here.
+		 */
+		if (!hv_isolation_type_snp()) {
+			hv_cpu->synic_message_page =
+				(void *)get_zeroed_page(GFP_ATOMIC);
+			if (hv_cpu->synic_message_page == NULL) {
+				pr_err("Unable to allocate SYNIC message page\n");
+				goto err;
+			}
 
-		hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
-		if (hv_cpu->synic_event_page == NULL) {
-			pr_err("Unable to allocate SYNIC event page\n");
-			goto err;
+			hv_cpu->synic_event_page =
+				(void *)get_zeroed_page(GFP_ATOMIC);
+			if (hv_cpu->synic_event_page == NULL) {
+				pr_err("Unable to allocate SYNIC event page\n");
+				goto err;
+			}
 		}
 
 		hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
@@ -173,10 +181,17 @@ void hv_synic_free(void)
 	for_each_present_cpu(cpu) {
 		struct hv_per_cpu_context *hv_cpu
 			= per_cpu_ptr(hv_context.cpu_context, cpu);
+		free_page((unsigned long)hv_cpu->post_msg_page);
+
+		/*
+		 * Synic message and event pages are allocated by paravisor.
+		 * Skip free these pages here.
+		 */
+		if (hv_isolation_type_snp())
+			continue;
 
 		free_page((unsigned long)hv_cpu->synic_event_page);
 		free_page((unsigned long)hv_cpu->synic_message_page);
-		free_page((unsigned long)hv_cpu->post_msg_page);
 	}
 
 	kfree(hv_context.hv_numa_map);
@@ -199,26 +214,43 @@ void hv_synic_enable_regs(unsigned int cpu)
 	union hv_synic_scontrol sctrl;
 
 	/* Setup the Synic's message page */
-	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+	hv_get_simp(simp.as_uint64);
 	simp.simp_enabled = 1;
-	simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
-		>> HV_HYP_PAGE_SHIFT;
 
-	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
+	if (hv_isolation_type_snp()) {
+		hv_cpu->synic_message_page
+			= memremap(simp.base_simp_gpa << HV_HYP_PAGE_SHIFT,
+				   HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+		if (!hv_cpu->synic_message_page)
+			pr_err("Fail to map syinc message page.\n");
+	} else {
+		simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
+			>> HV_HYP_PAGE_SHIFT;
+	}
+
+	hv_set_simp(simp.as_uint64);
 
 	/* Setup the Synic's event page */
-	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
+	hv_get_siefp(siefp.as_uint64);
 	siefp.siefp_enabled = 1;
-	siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
-		>> HV_HYP_PAGE_SHIFT;
 
-	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
+	if (hv_isolation_type_snp()) {
+		hv_cpu->synic_event_page =
+			memremap(siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT,
+				 HV_HYP_PAGE_SIZE, MEMREMAP_WB);
+
+		if (!hv_cpu->synic_event_page)
+			pr_err("Fail to map syinc event page.\n");
+	} else {
+		siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
+			>> HV_HYP_PAGE_SHIFT;
+	}
+	hv_set_siefp(siefp.as_uint64);
 
 	/* Setup the shared SINT. */
 	if (vmbus_irq != -1)
 		enable_percpu_irq(vmbus_irq, 0);
-	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
-					VMBUS_MESSAGE_SINT);
+	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 
 	shared_sint.vector = vmbus_interrupt;
 	shared_sint.masked = false;
@@ -233,14 +265,12 @@ void hv_synic_enable_regs(unsigned int cpu)
 #else
 	shared_sint.auto_eoi = 0;
 #endif
-	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
-				shared_sint.as_uint64);
+	hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 
 	/* Enable the global synic bit */
-	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
+	hv_get_synic_state(sctrl.as_uint64);
 	sctrl.enable = 1;
-
-	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
+	hv_set_synic_state(sctrl.as_uint64);
 }
 
 int hv_synic_init(unsigned int cpu)
@@ -257,37 +287,50 @@ int hv_synic_init(unsigned int cpu)
  */
 void hv_synic_disable_regs(unsigned int cpu)
 {
+	struct hv_per_cpu_context *hv_cpu
+		= per_cpu_ptr(hv_context.cpu_context, cpu);
 	union hv_synic_sint shared_sint;
 	union hv_synic_simp simp;
 	union hv_synic_siefp siefp;
 	union hv_synic_scontrol sctrl;
 
-	shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
-					VMBUS_MESSAGE_SINT);
-
+	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 	shared_sint.masked = 1;
+	hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
 
 	/* Need to correctly cleanup in the case of SMP!!! */
 	/* Disable the interrupt */
-	hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
-				shared_sint.as_uint64);
+	hv_get_simp(simp.as_uint64);
 
-	simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
+	/*
+	 * In Isolation VM, sim and sief pages are allocated by
+	 * paravisor. These pages also will be used by kdump
+	 * kernel. So just reset enable bit here and keep page
+	 * addresses.
+	 */
 	simp.simp_enabled = 0;
-	simp.base_simp_gpa = 0;
+	if (hv_isolation_type_snp())
+		memunmap(hv_cpu->synic_message_page);
+	else
+		simp.base_simp_gpa = 0;
 
-	hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
+	hv_set_simp(simp.as_uint64);
 
-	siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
+	hv_get_siefp(siefp.as_uint64);
 	siefp.siefp_enabled = 0;
-	siefp.base_siefp_gpa = 0;
 
-	hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
+	if (hv_isolation_type_snp())
+		memunmap(hv_cpu->synic_event_page);
+	else
+		siefp.base_siefp_gpa = 0;
+
+	hv_set_siefp(siefp.as_uint64);
 
 	/* Disable the global synic bit */
-	sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
+	hv_get_synic_state(sctrl.as_uint64);
 	sctrl.enable = 0;
-	hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
+	hv_set_synic_state(sctrl.as_uint64);
 
 	if (vmbus_irq != -1)
 		disable_percpu_irq(vmbus_irq);
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 2914e27b0429..e6d6886faed1 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -22,9 +22,16 @@
 #include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/cpumask.h>
+#include <asm/svm.h>
+#include <asm/sev-es.h>
 #include <asm/ptrace.h>
+#include <asm/mshyperv.h>
 #include <asm/hyperv-tlfs.h>
 
+union hv_ghcb {
+	struct ghcb ghcb;
+} __packed __aligned(PAGE_SIZE);
+
 struct ms_hyperv_info {
 	u32 features;
 	u32 priv_high;
@@ -44,13 +51,14 @@ struct ms_hyperv_info {
 			u32 Reserved12 : 20;
 		};
 	};
-	void  __percpu **ghcb_base;
+	union hv_ghcb __percpu **ghcb_base;
 	u64 shared_gpa_boundary;
 };
 extern struct ms_hyperv_info ms_hyperv;
 
 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
+extern bool hv_isolation_type_snp(void);
 
 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
 static inline int hv_result(u64 status)
@@ -145,7 +153,7 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 		 * possibly deliver another msg from the
 		 * hypervisor
 		 */
-		hv_set_register(HV_REGISTER_EOM, 0);
+		hv_signal_eom();
 	}
 }
 
-- 
2.25.1

[Resend RFC PATCH V4 06/13] HV: Add ghcb hvcall support for SNP VM

[Tianyu Lan]

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

Hyper-V provides ghcb hvcall to handle VMBus
HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE
msg in SNP Isolation VM. Add such support.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/ivm.c           | 42 +++++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h |  1 +
 drivers/hv/connection.c         |  6 ++++-
 drivers/hv/hv.c                 |  8 ++++++-
 include/asm-generic/mshyperv.h  | 29 +++++++++++++++++++++++
 5 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index c7b54631ca0d..8a6f4e9e3d6c 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -15,6 +15,48 @@
 #include <asm/io.h>
 #include <asm/mshyperv.h>
 
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size)
+{
+	union hv_ghcb *hv_ghcb;
+	void **ghcb_base;
+	unsigned long flags;
+
+	if (!ms_hyperv.ghcb_base)
+		return -EFAULT;
+
+	WARN_ON(in_nmi());
+
+	local_irq_save(flags);
+	ghcb_base = (void **)this_cpu_ptr(ms_hyperv.ghcb_base);
+	hv_ghcb = (union hv_ghcb *)*ghcb_base;
+	if (!hv_ghcb) {
+		local_irq_restore(flags);
+		return -EFAULT;
+	}
+
+	memset(hv_ghcb, 0x00, HV_HYP_PAGE_SIZE);
+	hv_ghcb->ghcb.protocol_version = 1;
+	hv_ghcb->ghcb.ghcb_usage = 1;
+
+	hv_ghcb->hypercall.outputgpa = (u64)output;
+	hv_ghcb->hypercall.hypercallinput.asuint64 = 0;
+	hv_ghcb->hypercall.hypercallinput.callcode = control;
+
+	if (input_size)
+		memcpy(hv_ghcb->hypercall.hypercalldata, input, input_size);
+
+	VMGEXIT();
+
+	hv_ghcb->ghcb.ghcb_usage = 0xffffffff;
+	memset(hv_ghcb->ghcb.save.valid_bitmap, 0,
+	       sizeof(hv_ghcb->ghcb.save.valid_bitmap));
+
+	local_irq_restore(flags);
+
+	return hv_ghcb->hypercall.hypercalloutput.callstatus;
+}
+EXPORT_SYMBOL_GPL(hv_ghcb_hypercall);
+
 void hv_ghcb_msr_write(u64 msr, u64 value)
 {
 	union hv_ghcb *hv_ghcb;
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f9cc3753040a..fe03e3e833ac 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -258,6 +258,7 @@ void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
 void hv_signal_eom_ghcb(void);
 void hv_ghcb_msr_write(u64 msr, u64 value);
 void hv_ghcb_msr_read(u64 msr, u64 *value);
+u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
 
 #define hv_get_synint_state_ghcb(int_num, val)			\
 	hv_sint_rdmsrl_ghcb(HV_X64_MSR_SINT0 + int_num, val)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 311cd005b3be..186fd4c8acd4 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -445,6 +445,10 @@ void vmbus_set_event(struct vmbus_channel *channel)
 
 	++channel->sig_events;
 
-	hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
+	if (hv_isolation_type_snp())
+		hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event,
+				NULL, sizeof(u64));
+	else
+		hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 59f7173c4d9f..e5c9fc467893 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -98,7 +98,13 @@ int hv_post_message(union hv_connection_id connection_id,
 	aligned_msg->payload_size = payload_size;
 	memcpy((void *)aligned_msg->payload, payload, payload_size);
 
-	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
+	if (hv_isolation_type_snp())
+		status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE,
+				(void *)aligned_msg, NULL,
+				sizeof(struct hv_input_post_message));
+	else
+		status = hv_do_hypercall(HVCALL_POST_MESSAGE,
+				aligned_msg, NULL);
 
 	/* Preemption must remain disabled until after the hypercall
 	 * so some other thread can't get scheduled onto this cpu and
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index e6d6886faed1..8f6f283fb5b5 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -30,6 +30,35 @@
 
 union hv_ghcb {
 	struct ghcb ghcb;
+	struct {
+		u64 hypercalldata[509];
+		u64 outputgpa;
+		union {
+			union {
+				struct {
+					u32 callcode        : 16;
+					u32 isfast          : 1;
+					u32 reserved1       : 14;
+					u32 isnested        : 1;
+					u32 countofelements : 12;
+					u32 reserved2       : 4;
+					u32 repstartindex   : 12;
+					u32 reserved3       : 4;
+				};
+				u64 asuint64;
+			} hypercallinput;
+			union {
+				struct {
+					u16 callstatus;
+					u16 reserved1;
+					u32 elementsprocessed : 12;
+					u32 reserved2         : 20;
+				};
+				u64 asunit64;
+			} hypercalloutput;
+		};
+		u64 reserved2;
+	} hypercall;
 } __packed __aligned(PAGE_SIZE);
 
 struct ms_hyperv_info {
-- 
2.25.1

[Resend RFC PATCH V4 07/13] HV/Vmbus: Add SNP support for VMbus channel initiate message

[Tianyu Lan]

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

The monitor pages in the CHANNELMSG_INITIATE_CONTACT msg are shared
with host in Isolation VM and so it's necessary to use hvcall to set
them visible to host. In Isolation VM with AMD SEV SNP, the access
address should be in the extra space which is above shared gpa
boundary. So remap these pages into the extra address(pa +
shared_gpa_boundary).

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/hv/connection.c   | 65 +++++++++++++++++++++++++++++++++++++++
 drivers/hv/hyperv_vmbus.h |  1 +
 2 files changed, 66 insertions(+)

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 186fd4c8acd4..a32bde143e4c 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -19,6 +19,7 @@
 #include <linux/vmalloc.h>
 #include <linux/hyperv.h>
 #include <linux/export.h>
+#include <linux/io.h>
 #include <asm/mshyperv.h>
 
 #include "hyperv_vmbus.h"
@@ -104,6 +105,12 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
 
 	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
 	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
+
+	if (hv_is_isolation_supported()) {
+		msg->monitor_page1 += ms_hyperv.shared_gpa_boundary;
+		msg->monitor_page2 += ms_hyperv.shared_gpa_boundary;
+	}
+
 	msg->target_vcpu = hv_cpu_number_to_vp_number(VMBUS_CONNECT_CPU);
 
 	/*
@@ -148,6 +155,31 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
 		return -ECONNREFUSED;
 	}
 
+	if (hv_is_isolation_supported()) {
+		vmbus_connection.monitor_pages_va[0]
+			= vmbus_connection.monitor_pages[0];
+		vmbus_connection.monitor_pages[0]
+			= memremap(msg->monitor_page1, HV_HYP_PAGE_SIZE,
+				   MEMREMAP_WB);
+		if (!vmbus_connection.monitor_pages[0])
+			return -ENOMEM;
+
+		vmbus_connection.monitor_pages_va[1]
+			= vmbus_connection.monitor_pages[1];
+		vmbus_connection.monitor_pages[1]
+			= memremap(msg->monitor_page2, HV_HYP_PAGE_SIZE,
+				   MEMREMAP_WB);
+		if (!vmbus_connection.monitor_pages[1]) {
+			memunmap(vmbus_connection.monitor_pages[0]);
+			return -ENOMEM;
+		}
+
+		memset(vmbus_connection.monitor_pages[0], 0x00,
+		       HV_HYP_PAGE_SIZE);
+		memset(vmbus_connection.monitor_pages[1], 0x00,
+		       HV_HYP_PAGE_SIZE);
+	}
+
 	return ret;
 }
 
@@ -159,6 +191,7 @@ int vmbus_connect(void)
 	struct vmbus_channel_msginfo *msginfo = NULL;
 	int i, ret = 0;
 	__u32 version;
+	u64 pfn[2];
 
 	/* Initialize the vmbus connection */
 	vmbus_connection.conn_state = CONNECTING;
@@ -216,6 +249,16 @@ int vmbus_connect(void)
 		goto cleanup;
 	}
 
+	if (hv_is_isolation_supported()) {
+		pfn[0] = virt_to_hvpfn(vmbus_connection.monitor_pages[0]);
+		pfn[1] = virt_to_hvpfn(vmbus_connection.monitor_pages[1]);
+		if (hv_mark_gpa_visibility(2, pfn,
+				VMBUS_PAGE_VISIBLE_READ_WRITE)) {
+			ret = -EFAULT;
+			goto cleanup;
+		}
+	}
+
 	msginfo = kzalloc(sizeof(*msginfo) +
 			  sizeof(struct vmbus_channel_initiate_contact),
 			  GFP_KERNEL);
@@ -282,6 +325,8 @@ int vmbus_connect(void)
 
 void vmbus_disconnect(void)
 {
+	u64 pfn[2];
+
 	/*
 	 * First send the unload request to the host.
 	 */
@@ -301,6 +346,26 @@ void vmbus_disconnect(void)
 		vmbus_connection.int_page = NULL;
 	}
 
+	if (hv_is_isolation_supported()) {
+		if (vmbus_connection.monitor_pages_va[0]) {
+			memunmap(vmbus_connection.monitor_pages[0]);
+			vmbus_connection.monitor_pages[0]
+				= vmbus_connection.monitor_pages_va[0];
+			vmbus_connection.monitor_pages_va[0] = NULL;
+		}
+
+		if (vmbus_connection.monitor_pages_va[1]) {
+			memunmap(vmbus_connection.monitor_pages[1]);
+			vmbus_connection.monitor_pages[1]
+				= vmbus_connection.monitor_pages_va[1];
+			vmbus_connection.monitor_pages_va[1] = NULL;
+		}
+
+		pfn[0] = virt_to_hvpfn(vmbus_connection.monitor_pages[0]);
+		pfn[1] = virt_to_hvpfn(vmbus_connection.monitor_pages[1]);
+		hv_mark_gpa_visibility(2, pfn, VMBUS_PAGE_NOT_VISIBLE);
+	}
+
 	hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]);
 	hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]);
 	vmbus_connection.monitor_pages[0] = NULL;
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 42f3d9d123a1..40bc0eff6665 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -240,6 +240,7 @@ struct vmbus_connection {
 	 * is child->parent notification
 	 */
 	struct hv_monitor_page *monitor_pages[2];
+	void *monitor_pages_va[2];
 	struct list_head chn_msg_list;
 	spinlock_t channelmsg_lock;
 
-- 
2.25.1

[Resend RFC PATCH V4 08/13] 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: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/hv/Kconfig        |  1 +
 drivers/hv/channel.c      | 10 +++++
 drivers/hv/hyperv_vmbus.h |  2 +
 drivers/hv/ring_buffer.c  | 84 ++++++++++++++++++++++++++++++---------
 4 files changed, 79 insertions(+), 18 deletions(-)

diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 66c794d92391..a8386998be40 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -7,6 +7,7 @@ config HYPERV
 	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
 	select PARAVIRT
 	select X86_HV_CALLBACK_VECTOR
+	select VMAP_PFN
 	help
 	  Select this option to run Linux as a Hyper-V client operating
 	  system.
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 01048bb07082..7350da9dbe97 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -707,6 +707,16 @@ 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 40bc0eff6665..15cd23a561f3 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, u32 max_pkt_size);
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 2aee356840a2..d4f93fca1108 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"
 
@@ -179,43 +181,89 @@ void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
 	mutex_init(&channel->outbound.ring_buffer_mutex);
 }
 
-/* Initialize the ring buffer. */
-int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
-		       struct page *pages, u32 page_cnt, u32 max_pkt_size)
+int hv_ringbuffer_post_init(struct hv_ring_buffer_info *ring_info,
+		       struct page *pages, u32 page_cnt)
 {
+	u64 physic_addr = page_to_pfn(pages) << PAGE_SHIFT;
+	unsigned long *pfns_wraparound;
+	void *vaddr;
 	int i;
-	struct page **pages_wraparound;
 
-	BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
+	if (!hv_isolation_type_snp())
+		return 0;
+
+	physic_addr += ms_hyperv.shared_gpa_boundary;
 
 	/*
 	 * First page holds struct hv_ring_buffer, do wraparound mapping for
 	 * the rest.
 	 */
-	pages_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(struct page *),
+	pfns_wraparound = kcalloc(page_cnt * 2 - 1, sizeof(unsigned long),
 				   GFP_KERNEL);
-	if (!pages_wraparound)
+	if (!pfns_wraparound)
 		return -ENOMEM;
 
-	pages_wraparound[0] = pages;
+	pfns_wraparound[0] = physic_addr >> PAGE_SHIFT;
 	for (i = 0; i < 2 * (page_cnt - 1); i++)
-		pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
-
-	ring_info->ring_buffer = (struct hv_ring_buffer *)
-		vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL);
-
-	kfree(pages_wraparound);
+		pfns_wraparound[i + 1] = (physic_addr >> PAGE_SHIFT) +
+			i % (page_cnt - 1) + 1;
 
-
-	if (!ring_info->ring_buffer)
+	vaddr = vmap_pfn(pfns_wraparound, page_cnt * 2 - 1, PAGE_KERNEL_IO);
+	kfree(pfns_wraparound);
+	if (!vaddr)
 		return -ENOMEM;
 
-	ring_info->ring_buffer->read_index =
-		ring_info->ring_buffer->write_index = 0;
+	/* 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;
 
 	/* Set the feature bit for enabling flow control. */
 	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, u32 max_pkt_size)
+{
+	int i;
+	struct page **pages_wraparound;
+
+	BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE));
+
+	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;
+
+		pages_wraparound[0] = pages;
+		for (i = 0; i < 2 * (page_cnt - 1); i++)
+			pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1];
+
+		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;
+
+		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;
+	}
+
 	ring_info->ring_size = page_cnt << PAGE_SHIFT;
 	ring_info->ring_size_div10_reciprocal =
 		reciprocal_value(ring_info->ring_size / 10);
-- 
2.25.1

[Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Tianyu Lan]

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

In Isolation VM with AMD SEV, bounce buffer needs to be accessed via
extra address space which is above shared_gpa_boundary
(E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
The access physical address will be original physical address +
shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
spec is called virtual top of memory(vTOM). Memory addresses below
vTOM are automatically treated as private while memory above
vTOM is treated as shared.

Introduce set_memory_decrypted_map() function to decrypt memory and
remap memory with platform callback. Use set_memory_decrypted_
map() in the swiotlb code, store remap address returned by the new
API and use the remap address to copy data from/to swiotlb bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/hyperv/ivm.c             | 30 ++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h   |  2 ++
 arch/x86/include/asm/set_memory.h |  2 ++
 arch/x86/mm/pat/set_memory.c      | 28 ++++++++++++++++++++++++++++
 include/linux/swiotlb.h           |  4 ++++
 kernel/dma/swiotlb.c              | 11 ++++++++---
 6 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 8a6f4e9e3d6c..ea33935e0c17 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -267,3 +267,33 @@ int hv_set_mem_enc(unsigned long addr, int numpages, bool enc)
 			enc ? VMBUS_PAGE_NOT_VISIBLE
 			: VMBUS_PAGE_VISIBLE_READ_WRITE);
 }
+
+/*
+ * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
+ */
+unsigned long hv_map_memory(unsigned long addr, unsigned long size)
+{
+	unsigned long *pfns = kcalloc(size / HV_HYP_PAGE_SIZE,
+				      sizeof(unsigned long),
+		       GFP_KERNEL);
+	unsigned long vaddr;
+	int i;
+
+	if (!pfns)
+		return (unsigned long)NULL;
+
+	for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
+		pfns[i] = virt_to_hvpfn((void *)addr + i * HV_HYP_PAGE_SIZE) +
+			(ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
+
+	vaddr = (unsigned long)vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE,
+					PAGE_KERNEL_IO);
+	kfree(pfns);
+
+	return vaddr;
+}
+
+void hv_unmap_memory(unsigned long addr)
+{
+	vunmap((void *)addr);
+}
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index fe03e3e833ac..ba3cb9e32fdb 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -253,6 +253,8 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
 int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
 int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility);
 int hv_set_mem_enc(unsigned long addr, int numpages, bool enc);
+unsigned long hv_map_memory(unsigned long addr, unsigned long size);
+void hv_unmap_memory(unsigned long addr);
 void hv_sint_wrmsrl_ghcb(u64 msr, u64 value);
 void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
 void hv_signal_eom_ghcb(void);
diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 43fa081a1adb..7a2117931830 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -49,6 +49,8 @@ int set_memory_decrypted(unsigned long addr, int numpages);
 int set_memory_np_noalias(unsigned long addr, int numpages);
 int set_memory_nonglobal(unsigned long addr, int numpages);
 int set_memory_global(unsigned long addr, int numpages);
+unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size);
+int set_memory_encrypted_unmap(unsigned long addr, unsigned long size);
 
 int set_pages_array_uc(struct page **pages, int addrinarray);
 int set_pages_array_wc(struct page **pages, int addrinarray);
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 6cc83c57383d..5d4d3963f4a2 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2039,6 +2039,34 @@ int set_memory_decrypted(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL_GPL(set_memory_decrypted);
 
+static unsigned long __map_memory(unsigned long addr, unsigned long size)
+{
+	if (hv_is_isolation_supported())
+		return hv_map_memory(addr, size);
+
+	return addr;
+}
+
+static void __unmap_memory(unsigned long addr)
+{
+	if (hv_is_isolation_supported())
+		hv_unmap_memory(addr);
+}
+
+unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size)
+{
+	if (__set_memory_enc_dec(addr, size / PAGE_SIZE, false))
+		return (unsigned long)NULL;
+
+	return __map_memory(addr, size);
+}
+
+int set_memory_encrypted_unmap(unsigned long addr, unsigned long size)
+{
+	__unmap_memory(addr);
+	return __set_memory_enc_dec(addr, size / PAGE_SIZE, true);
+}
+
 int set_pages_uc(struct page *page, int numpages)
 {
 	unsigned long addr = (unsigned long)page_address(page);
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index f507e3eacbea..5c6f6c7380ef 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -72,6 +72,9 @@ extern enum swiotlb_force swiotlb_force;
  * @end:	The end address of the swiotlb memory pool. Used to do a quick
  *		range check to see if the memory was in fact allocated by this
  *		API.
+ * @vstart:	The virtual start address of the swiotlb memory pool. The swiotlb
+ *		memory pool may be remapped in the memory encrypted case and store
+ *		virtual address for bounce buffer operation.
  * @nslabs:	The number of IO TLB blocks (in groups of 64) between @start and
  *		@end. For default swiotlb, this is command line adjustable via
  *		setup_io_tlb_npages.
@@ -89,6 +92,7 @@ extern enum swiotlb_force swiotlb_force;
 struct io_tlb_mem {
 	phys_addr_t start;
 	phys_addr_t end;
+	void *vstart;
 	unsigned long nslabs;
 	unsigned long used;
 	unsigned int index;
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d3fa4669229b..9911817250a8 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -194,8 +194,13 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
 		mem->slots[i].alloc_size = 0;
 	}
 
-	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
-	memset(vaddr, 0, bytes);
+	mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
+	if (!mem->vstart) {
+		pr_err("Failed to decrypt memory.\n");
+		return;
+	}
+
+	memset(mem->vstart, 0, bytes);
 }
 
 int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
@@ -352,7 +357,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
 	phys_addr_t orig_addr = mem->slots[index].orig_addr;
 	size_t alloc_size = mem->slots[index].alloc_size;
 	unsigned long pfn = PFN_DOWN(orig_addr);
-	unsigned char *vaddr = phys_to_virt(tlb_addr);
+	unsigned char *vaddr = mem->vstart + tlb_addr - mem->start;
 
 	if (orig_addr == INVALID_PHYS_ADDR)
 		return;
-- 
2.25.1

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Tianyu Lan]

Hi Christoph & Konrad:
     Could you review this patch and make sure this is right way to 
resolve the memory remap request from AMD SEV-SNP vTOM case?

Thanks.

On 7/7/2021 11:46 PM, Tianyu Lan wrote:
> From: Tianyu Lan <Tianyu.Lan@microsoft.com>
> 
> In Isolation VM with AMD SEV, bounce buffer needs to be accessed via
> extra address space which is above shared_gpa_boundary
> (E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
> The access physical address will be original physical address +
> shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
> spec is called virtual top of memory(vTOM). Memory addresses below
> vTOM are automatically treated as private while memory above
> vTOM is treated as shared.
> 
> Introduce set_memory_decrypted_map() function to decrypt memory and
> remap memory with platform callback. Use set_memory_decrypted_
> map() in the swiotlb code, store remap address returned by the new
> API and use the remap address to copy data from/to swiotlb bounce buffer.
> 
> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
> ---
>   arch/x86/hyperv/ivm.c             | 30 ++++++++++++++++++++++++++++++
>   arch/x86/include/asm/mshyperv.h   |  2 ++
>   arch/x86/include/asm/set_memory.h |  2 ++
>   arch/x86/mm/pat/set_memory.c      | 28 ++++++++++++++++++++++++++++
>   include/linux/swiotlb.h           |  4 ++++
>   kernel/dma/swiotlb.c              | 11 ++++++++---
>   6 files changed, 74 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
> index 8a6f4e9e3d6c..ea33935e0c17 100644
> --- a/arch/x86/hyperv/ivm.c
> +++ b/arch/x86/hyperv/ivm.c
> @@ -267,3 +267,33 @@ int hv_set_mem_enc(unsigned long addr, int numpages, bool enc)
>   			enc ? VMBUS_PAGE_NOT_VISIBLE
>   			: VMBUS_PAGE_VISIBLE_READ_WRITE);
>   }
> +
> +/*
> + * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
> + */
> +unsigned long hv_map_memory(unsigned long addr, unsigned long size)
> +{
> +	unsigned long *pfns = kcalloc(size / HV_HYP_PAGE_SIZE,
> +				      sizeof(unsigned long),
> +		       GFP_KERNEL);
> +	unsigned long vaddr;
> +	int i;
> +
> +	if (!pfns)
> +		return (unsigned long)NULL;
> +
> +	for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
> +		pfns[i] = virt_to_hvpfn((void *)addr + i * HV_HYP_PAGE_SIZE) +
> +			(ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
> +
> +	vaddr = (unsigned long)vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE,
> +					PAGE_KERNEL_IO);
> +	kfree(pfns);
> +
> +	return vaddr;
> +}
> +
> +void hv_unmap_memory(unsigned long addr)
> +{
> +	vunmap((void *)addr);
> +}
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index fe03e3e833ac..ba3cb9e32fdb 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -253,6 +253,8 @@ int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
>   int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
>   int hv_mark_gpa_visibility(u16 count, const u64 pfn[], u32 visibility);
>   int hv_set_mem_enc(unsigned long addr, int numpages, bool enc);
> +unsigned long hv_map_memory(unsigned long addr, unsigned long size);
> +void hv_unmap_memory(unsigned long addr);
>   void hv_sint_wrmsrl_ghcb(u64 msr, u64 value);
>   void hv_sint_rdmsrl_ghcb(u64 msr, u64 *value);
>   void hv_signal_eom_ghcb(void);
> diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
> index 43fa081a1adb..7a2117931830 100644
> --- a/arch/x86/include/asm/set_memory.h
> +++ b/arch/x86/include/asm/set_memory.h
> @@ -49,6 +49,8 @@ int set_memory_decrypted(unsigned long addr, int numpages);
>   int set_memory_np_noalias(unsigned long addr, int numpages);
>   int set_memory_nonglobal(unsigned long addr, int numpages);
>   int set_memory_global(unsigned long addr, int numpages);
> +unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size);
> +int set_memory_encrypted_unmap(unsigned long addr, unsigned long size);
>   
>   int set_pages_array_uc(struct page **pages, int addrinarray);
>   int set_pages_array_wc(struct page **pages, int addrinarray);
> diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
> index 6cc83c57383d..5d4d3963f4a2 100644
> --- a/arch/x86/mm/pat/set_memory.c
> +++ b/arch/x86/mm/pat/set_memory.c
> @@ -2039,6 +2039,34 @@ int set_memory_decrypted(unsigned long addr, int numpages)
>   }
>   EXPORT_SYMBOL_GPL(set_memory_decrypted);
>   
> +static unsigned long __map_memory(unsigned long addr, unsigned long size)
> +{
> +	if (hv_is_isolation_supported())
> +		return hv_map_memory(addr, size);
> +
> +	return addr;
> +}
> +
> +static void __unmap_memory(unsigned long addr)
> +{
> +	if (hv_is_isolation_supported())
> +		hv_unmap_memory(addr);
> +}
> +
> +unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size)
> +{
> +	if (__set_memory_enc_dec(addr, size / PAGE_SIZE, false))
> +		return (unsigned long)NULL;
> +
> +	return __map_memory(addr, size);
> +}
> +
> +int set_memory_encrypted_unmap(unsigned long addr, unsigned long size)
> +{
> +	__unmap_memory(addr);
> +	return __set_memory_enc_dec(addr, size / PAGE_SIZE, true);
> +}
> +
>   int set_pages_uc(struct page *page, int numpages)
>   {
>   	unsigned long addr = (unsigned long)page_address(page);
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index f507e3eacbea..5c6f6c7380ef 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -72,6 +72,9 @@ extern enum swiotlb_force swiotlb_force;
>    * @end:	The end address of the swiotlb memory pool. Used to do a quick
>    *		range check to see if the memory was in fact allocated by this
>    *		API.
> + * @vstart:	The virtual start address of the swiotlb memory pool. The swiotlb
> + *		memory pool may be remapped in the memory encrypted case and store
> + *		virtual address for bounce buffer operation.
>    * @nslabs:	The number of IO TLB blocks (in groups of 64) between @start and
>    *		@end. For default swiotlb, this is command line adjustable via
>    *		setup_io_tlb_npages.
> @@ -89,6 +92,7 @@ extern enum swiotlb_force swiotlb_force;
>   struct io_tlb_mem {
>   	phys_addr_t start;
>   	phys_addr_t end;
> +	void *vstart;
>   	unsigned long nslabs;
>   	unsigned long used;
>   	unsigned int index;
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index d3fa4669229b..9911817250a8 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -194,8 +194,13 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
>   		mem->slots[i].alloc_size = 0;
>   	}
>   
> -	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> -	memset(vaddr, 0, bytes);
> +	mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
> +	if (!mem->vstart) {
> +		pr_err("Failed to decrypt memory.\n");
> +		return;
> +	}
> +
> +	memset(mem->vstart, 0, bytes);
>   }
>   
>   int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> @@ -352,7 +357,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
>   	phys_addr_t orig_addr = mem->slots[index].orig_addr;
>   	size_t alloc_size = mem->slots[index].alloc_size;
>   	unsigned long pfn = PFN_DOWN(orig_addr);
> -	unsigned char *vaddr = phys_to_virt(tlb_addr);
> +	unsigned char *vaddr = mem->vstart + tlb_addr - mem->start;
>   
>   	if (orig_addr == INVALID_PHYS_ADDR)
>   		return;
> 

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Christoph Hellwig]

Please split the swiotlb changes into a separate patch from the
consumer.

>  }
> +
> +/*
> + * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
> + */
> +unsigned long hv_map_memory(unsigned long addr, unsigned long size)
> +{
> +	unsigned long *pfns = kcalloc(size / HV_HYP_PAGE_SIZE,
> +				      sizeof(unsigned long),
> +		       GFP_KERNEL);
> +	unsigned long vaddr;
> +	int i;
> +
> +	if (!pfns)
> +		return (unsigned long)NULL;
> +
> +	for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
> +		pfns[i] = virt_to_hvpfn((void *)addr + i * HV_HYP_PAGE_SIZE) +
> +			(ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
> +
> +	vaddr = (unsigned long)vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE,
> +					PAGE_KERNEL_IO);
> +	kfree(pfns);
> +
> +	return vaddr;

This seems to miss a 'select VMAP_PFN'.  But more importantly I don't
think this actually works.  Various DMA APIs do expect a struct page
backing, so how is this going to work with say dma_mmap_attrs or
dma_get_sgtable_attrs?

> +static unsigned long __map_memory(unsigned long addr, unsigned long size)
> +{
> +	if (hv_is_isolation_supported())
> +		return hv_map_memory(addr, size);
> +
> +	return addr;
> +}
> +
> +static void __unmap_memory(unsigned long addr)
> +{
> +	if (hv_is_isolation_supported())
> +		hv_unmap_memory(addr);
> +}
> +
> +unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size)
> +{
> +	if (__set_memory_enc_dec(addr, size / PAGE_SIZE, false))
> +		return (unsigned long)NULL;
> +
> +	return __map_memory(addr, size);
> +}
> +
> +int set_memory_encrypted_unmap(unsigned long addr, unsigned long size)
> +{
> +	__unmap_memory(addr);
> +	return __set_memory_enc_dec(addr, size / PAGE_SIZE, true);
> +}

Why this obsfucation into all kinds of strange helpers?  Also I think
we want an ops vectors (or alternative calls) instead of the random
if checks here.

> + * @vstart:	The virtual start address of the swiotlb memory pool. The swiotlb
> + *		memory pool may be remapped in the memory encrypted case and store

Normall we'd call this vaddr or cpu_addr.

> -	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> -	memset(vaddr, 0, bytes);
> +	mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);

Please always pass kernel virtual addresses as pointers.

And I think these APIs might need better names, e.g.

arch_dma_map_decrypted and arch_dma_unmap_decrypted.

Also these will need fallback versions for non-x86 architectures that
currently use memory encryption.

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Tianyu Lan]

Thanks for review.

On 7/20/2021 9:54 PM, Christoph Hellwig wrote:
> 
> Please split the swiotlb changes into a separate patch from the
> consumer.

OK. Will update.

> 
>>   }
>> +
>> +/*
>> + * hv_map_memory - map memory to extra space in the AMD SEV-SNP Isolation VM.
>> + */
>> +unsigned long hv_map_memory(unsigned long addr, unsigned long size)
>> +{
>> +	unsigned long *pfns = kcalloc(size / HV_HYP_PAGE_SIZE,
>> +				      sizeof(unsigned long),
>> +		       GFP_KERNEL);
>> +	unsigned long vaddr;
>> +	int i;
>> +
>> +	if (!pfns)
>> +		return (unsigned long)NULL;
>> +
>> +	for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
>> +		pfns[i] = virt_to_hvpfn((void *)addr + i * HV_HYP_PAGE_SIZE) +
>> +			(ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
>> +
>> +	vaddr = (unsigned long)vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE,
>> +					PAGE_KERNEL_IO);
>> +	kfree(pfns);
>> +
>> +	return vaddr;
> 
> This seems to miss a 'select VMAP_PFN'. 

VMAP_PFN has been selected in the previous patch "RFC PATCH V4 08/13]
HV/Vmbus: Initialize VMbus ring buffer for Isolation VM"

> But more importantly I don't
> think this actually works.  Various DMA APIs do expect a struct page
> backing, so how is this going to work with say dma_mmap_attrs or
> dma_get_sgtable_attrs?

dma_mmap_attrs() and dma_get_sgtable_attrs() get input virtual address
belonging to backing memory with struct page and returns bounce buffer
dma physical address which is below shared_gpa_boundary(vTOM) and passed
to Hyper-V via vmbus protocol.

The new map virtual address is only to access bounce buffer in swiotlb
code and will not be used other places. It's stored in the mem->vstart.
So the new API set_memory_decrypted_map() in this series is only called
in the swiotlb code. Other platforms may replace set_memory_decrypted()
with set_memory_decrypted_map() as requested.

> 
>> +static unsigned long __map_memory(unsigned long addr, unsigned long size)
>> +{
>> +	if (hv_is_isolation_supported())
>> +		return hv_map_memory(addr, size);
>> +
>> +	return addr;
>> +}
>> +
>> +static void __unmap_memory(unsigned long addr)
>> +{
>> +	if (hv_is_isolation_supported())
>> +		hv_unmap_memory(addr);
>> +}
>> +
>> +unsigned long set_memory_decrypted_map(unsigned long addr, unsigned long size)
>> +{
>> +	if (__set_memory_enc_dec(addr, size / PAGE_SIZE, false))
>> +		return (unsigned long)NULL;
>> +
>> +	return __map_memory(addr, size);
>> +}
>> +
>> +int set_memory_encrypted_unmap(unsigned long addr, unsigned long size)
>> +{
>> +	__unmap_memory(addr);
>> +	return __set_memory_enc_dec(addr, size / PAGE_SIZE, true);
>> +}
> 
> Why this obsfucation into all kinds of strange helpers?  Also I think
> we want an ops vectors (or alternative calls) instead of the random
> if checks here.

Yes, agree and will add ops for different platforms to map/unmap memory.

> 
>> + * @vstart:	The virtual start address of the swiotlb memory pool. The swiotlb
>> + *		memory pool may be remapped in the memory encrypted case and store
> 
> Normall we'd call this vaddr or cpu_addr.

OK. Will update.

> 
>> -	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
>> -	memset(vaddr, 0, bytes);
>> +	mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
> 
> Please always pass kernel virtual addresses as pointers.
> 
> And I think these APIs might need better names, e.g.
> 
> arch_dma_map_decrypted and arch_dma_unmap_decrypted.
> 
> Also these will need fallback versions for non-x86 architectures that
> currently use memory encryption.

Sure. Will update in the next version.

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Christoph Hellwig]

On Wed, Jul 21, 2021 at 06:28:48PM +0800, Tianyu Lan wrote:
> dma_mmap_attrs() and dma_get_sgtable_attrs() get input virtual address
> belonging to backing memory with struct page and returns bounce buffer
> dma physical address which is below shared_gpa_boundary(vTOM) and passed
> to Hyper-V via vmbus protocol.
>
> The new map virtual address is only to access bounce buffer in swiotlb
> code and will not be used other places. It's stored in the mem->vstart.
> So the new API set_memory_decrypted_map() in this series is only called
> in the swiotlb code. Other platforms may replace set_memory_decrypted()
> with set_memory_decrypted_map() as requested.

It seems like you are indeed not using these new helpers in
dma_direct_alloc.  How is dma_alloc_attrs/dma_alloc_coherent going to
work on these systems?

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Tianyu Lan]

On 7/21/2021 10:33 PM, Christoph Hellwig wrote:
> On Wed, Jul 21, 2021 at 06:28:48PM +0800, Tianyu Lan wrote:
>> dma_mmap_attrs() and dma_get_sgtable_attrs() get input virtual address
>> belonging to backing memory with struct page and returns bounce buffer
>> dma physical address which is below shared_gpa_boundary(vTOM) and passed
>> to Hyper-V via vmbus protocol.
>>
>> The new map virtual address is only to access bounce buffer in swiotlb
>> code and will not be used other places. It's stored in the mem->vstart.
>> So the new API set_memory_decrypted_map() in this series is only called
>> in the swiotlb code. Other platforms may replace set_memory_decrypted()
>> with set_memory_decrypted_map() as requested.
> 
> It seems like you are indeed not using these new helpers in
> dma_direct_alloc.  How is dma_alloc_attrs/dma_alloc_coherent going to
> work on these systems?
> 

Current vmbus device drivers don't use dma_alloc_attrs/dma_alloc
_coherent() because vmbus driver allocates ring buffer for all devices. 
Ring buffer has been marked decrypted and remapped in vmbus driver. 
Netvsc and storvsc drivers just need to use  dma_map_single/dma_map_page().

Re: [Resend RFC PATCH V4 09/13] x86/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM

[Tianyu Lan]

Hi Christoph:
       I followed your this suggestion to rework the latest
version(https://lkml.org/lkml/2021/8/9/805). I just remove the arch
prefix from your suggested name arch_dma_map_decrypted because the 
platform may populate their map/umap callback in the ops. But from your 
latest comment(https://lkml.org/lkml/2021/8/12/149), these names confuse 
vs the actual dma_map_* calls... Could you help to give the right 
function name? The new map function is to map bounce buffer in the 
trust/Isolation VM and these buffers are DMA memory.



On 7/20/2021 9:54 PM, Christoph Hellwig wrote:
>> -	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
>> -	memset(vaddr, 0, bytes);
>> +	mem->vstart = (void *)set_memory_decrypted_map((unsigned long)vaddr, bytes);
> Please always pass kernel virtual addresses as pointers.
> 
> And I think these APIs might need better names, e.g.
> 
> arch_dma_map_decrypted and arch_dma_unmap_decrypted.
> 
> Also these will need fallback versions for non-x86 architectures that
> currently use memory encryption.

[Resend RFC PATCH V4 10/13] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM

[Tianyu Lan]

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

Hyper-V Isolation VM requires bounce buffer support to copy
data from/to encrypted memory and so enable swiotlb force
mode to use swiotlb bounce buffer for DMA transaction.

In Isolation VM with AMD SEV, the bounce buffer needs to be
accessed via extra address space which is above shared_gpa_boundary
(E.G 39 bit address line) reported by Hyper-V CPUID ISOLATION_CONFIG.
The access physical address will be original physical address +
shared_gpa_boundary. The shared_gpa_boundary in the AMD SEV SNP
spec is called virtual top of memory(vTOM). Memory addresses below
vTOM are automatically treated as private while memory above
vTOM is treated as shared.

Swiotlb bounce buffer code calls set_memory_decrypted_map()
to mark bounce buffer visible to host and map it in extra
address space.

Hyper-V initalizes swiotlb bounce buffer and default swiotlb
needs to be disabled. pci_swiotlb_detect_override() and
pci_swiotlb_detect_4gb() enable the default one. To override
the setting, hyperv_swiotlb_detect() needs to run before
these detect functions which depends on the pci_xen_swiotlb_
init(). Make pci_xen_swiotlb_init() depends on the hyperv_swiotlb
_detect() to keep the order.

The map function vmap_pfn() can't work in the early place
hyperv_iommu_swiotlb_init() and so initialize swiotlb bounce
buffer in the hyperv_iommu_swiotlb_later_init().

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/xen/pci-swiotlb-xen.c |  3 +-
 drivers/hv/vmbus_drv.c         |  3 ++
 drivers/iommu/hyperv-iommu.c   | 62 ++++++++++++++++++++++++++++++++++
 include/linux/hyperv.h         |  1 +
 4 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index 54f9aa7e8457..43bd031aa332 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -4,6 +4,7 @@
 
 #include <linux/dma-map-ops.h>
 #include <linux/pci.h>
+#include <linux/hyperv.h>
 #include <xen/swiotlb-xen.h>
 
 #include <asm/xen/hypervisor.h>
@@ -91,6 +92,6 @@ int pci_xen_swiotlb_init_late(void)
 EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
 
 IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
-		  NULL,
+		  hyperv_swiotlb_detect,
 		  pci_xen_swiotlb_init,
 		  NULL);
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 92cb3f7d21d9..5e3bb76d4dee 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -23,6 +23,7 @@
 #include <linux/cpu.h>
 #include <linux/sched/task_stack.h>
 
+#include <linux/dma-map-ops.h>
 #include <linux/delay.h>
 #include <linux/notifier.h>
 #include <linux/ptrace.h>
@@ -2080,6 +2081,7 @@ struct hv_device *vmbus_device_create(const guid_t *type,
 	return child_device_obj;
 }
 
+static u64 vmbus_dma_mask = DMA_BIT_MASK(64);
 /*
  * vmbus_device_register - Register the child device
  */
@@ -2120,6 +2122,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 	}
 	hv_debug_add_dev_dir(child_device_obj);
 
+	child_device_obj->device.dma_mask = &vmbus_dma_mask;
 	return 0;
 
 err_kset_unregister:
diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c
index e285a220c913..d7ea8e05b991 100644
--- a/drivers/iommu/hyperv-iommu.c
+++ b/drivers/iommu/hyperv-iommu.c
@@ -13,14 +13,22 @@
 #include <linux/irq.h>
 #include <linux/iommu.h>
 #include <linux/module.h>
+#include <linux/hyperv.h>
+#include <linux/io.h>
 
 #include <asm/apic.h>
 #include <asm/cpu.h>
 #include <asm/hw_irq.h>
 #include <asm/io_apic.h>
+#include <asm/iommu.h>
+#include <asm/iommu_table.h>
 #include <asm/irq_remapping.h>
 #include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
+#include <asm/swiotlb.h>
+#include <linux/dma-map-ops.h>
+#include <linux/dma-direct.h>
+#include <linux/set_memory.h>
 
 #include "irq_remapping.h"
 
@@ -36,6 +44,8 @@
 static cpumask_t ioapic_max_cpumask = { CPU_BITS_NONE };
 static struct irq_domain *ioapic_ir_domain;
 
+static unsigned long hyperv_io_tlb_start, hyperv_io_tlb_size;
+
 static int hyperv_ir_set_affinity(struct irq_data *data,
 		const struct cpumask *mask, bool force)
 {
@@ -337,4 +347,56 @@ static const struct irq_domain_ops hyperv_root_ir_domain_ops = {
 	.free = hyperv_root_irq_remapping_free,
 };
 
+void __init hyperv_iommu_swiotlb_init(void)
+{
+	unsigned long bytes;
+	void *vstart;
+
+	/*
+	 * Allocate Hyper-V swiotlb bounce buffer at early place
+	 * to reserve large contiguous memory.
+	 */
+	hyperv_io_tlb_size = 200 * 1024 * 1024;
+	hyperv_io_tlb_start = memblock_alloc_low(PAGE_ALIGN(hyperv_io_tlb_size),
+						 HV_HYP_PAGE_SIZE);
+
+	if (!hyperv_io_tlb_start) {
+		pr_warn("Fail to allocate Hyper-V swiotlb buffer.\n");
+		return;
+	}
+}
+
+int __init hyperv_swiotlb_detect(void)
+{
+	if (hypervisor_is_type(X86_HYPER_MS_HYPERV)
+	    && hv_is_isolation_supported()) {
+		/*
+		 * Enable swiotlb force mode in Isolation VM to
+		 * use swiotlb bounce buffer for dma transaction.
+		 */
+		swiotlb_force = SWIOTLB_FORCE;
+		return 1;
+	}
+
+	return 0;
+}
+
+void __init hyperv_iommu_swiotlb_later_init(void)
+{
+	void *hyperv_io_tlb_remap;
+	int ret;
+
+	/*
+	 * Swiotlb bounce buffer needs to be mapped in extra address
+	 * space. Map function doesn't work in the early place and so
+	 * call swiotlb_late_init_with_tbl() here.
+	 */
+	swiotlb_late_init_with_tbl(hyperv_io_tlb_start,
+				   hyperv_io_tlb_size >> IO_TLB_SHIFT);
+}
+
+IOMMU_INIT_FINISH(hyperv_swiotlb_detect,
+		  NULL, hyperv_iommu_swiotlb_init,
+		  hyperv_iommu_swiotlb_later_init);
+
 #endif
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 06eccaba10c5..babbe19f57e2 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1759,6 +1759,7 @@ int hyperv_write_cfg_blk(struct pci_dev *dev, void *buf, unsigned int len,
 int hyperv_reg_block_invalidate(struct pci_dev *dev, void *context,
 				void (*block_invalidate)(void *context,
 							 u64 block_mask));
+int __init hyperv_swiotlb_detect(void);
 
 struct hyperv_pci_block_ops {
 	int (*read_block)(struct pci_dev *dev, void *buf, unsigned int buf_len,
-- 
2.25.1

[Resend RFC PATCH V4 11/13] HV/Netvsc: Add Isolation VM support for netvsc driver

[Tianyu Lan]

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

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() still need to handle. Use DMA API to map/umap these
memory during sending/receiving packet and Hyper-V DMA ops callback
will use swiotlb function to allocate bounce buffer and copy data
from/to bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |   6 ++
 drivers/net/hyperv/netvsc.c       | 144 +++++++++++++++++++++++++++++-
 drivers/net/hyperv/rndis_filter.c |   2 +
 include/linux/hyperv.h            |   5 ++
 4 files changed, 154 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index b11aa68b44ec..c2fbb9d4df2c 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -164,6 +164,7 @@ struct hv_netvsc_packet {
 	u32 total_bytes;
 	u32 send_buf_index;
 	u32 total_data_buflen;
+	struct hv_dma_range *dma_range;
 };
 
 #define NETVSC_HASH_KEYLEN 40
@@ -1074,6 +1075,7 @@ 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 */
 	u32 recv_buf_gpadl_handle;
 	u32 recv_section_cnt;
@@ -1082,6 +1084,8 @@ struct netvsc_device {
 
 	/* Send buffer allocated by us */
 	void *send_buf;
+	void *send_original_buf;
+	u32 send_buf_size;
 	u32 send_buf_gpadl_handle;
 	u32 send_section_cnt;
 	u32 send_section_size;
@@ -1729,4 +1733,6 @@ struct rndis_message {
 #define RETRY_US_HI	10000
 #define RETRY_MAX	2000	/* >10 sec */
 
+void netvsc_dma_unmap(struct hv_device *hv_dev,
+		      struct hv_netvsc_packet *packet);
 #endif /* _HYPERV_NET_H */
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7bd935412853..fc312e5db4d5 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -153,8 +153,21 @@ static void free_netvsc_device(struct rcu_head *head)
 	int i;
 
 	kfree(nvdev->extension);
-	vfree(nvdev->recv_buf);
-	vfree(nvdev->send_buf);
+
+	if (nvdev->recv_original_buf) {
+		vunmap(nvdev->recv_buf);
+		vfree(nvdev->recv_original_buf);
+	} else {
+		vfree(nvdev->recv_buf);
+	}
+
+	if (nvdev->send_original_buf) {
+		vunmap(nvdev->send_buf);
+		vfree(nvdev->send_original_buf);
+	} else {
+		vfree(nvdev->send_buf);
+	}
+
 	kfree(nvdev->send_section_map);
 
 	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
@@ -330,6 +343,27 @@ int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
 	return nvchan->mrc.slots ? 0 : -ENOMEM;
 }
 
+static void *netvsc_remap_buf(void *buf, unsigned long size)
+{
+	unsigned long *pfns;
+	void *vaddr;
+	int i;
+
+	pfns = kcalloc(size / HV_HYP_PAGE_SIZE, sizeof(unsigned long),
+		       GFP_KERNEL);
+	if (!pfns)
+		return NULL;
+
+	for (i = 0; i < size / HV_HYP_PAGE_SIZE; i++)
+		pfns[i] = virt_to_hvpfn(buf + i * HV_HYP_PAGE_SIZE)
+			+ (ms_hyperv.shared_gpa_boundary >> HV_HYP_PAGE_SHIFT);
+
+	vaddr = vmap_pfn(pfns, size / HV_HYP_PAGE_SIZE, PAGE_KERNEL_IO);
+	kfree(pfns);
+
+	return vaddr;
+}
+
 static int netvsc_init_buf(struct hv_device *device,
 			   struct netvsc_device *net_device,
 			   const struct netvsc_device_info *device_info)
@@ -340,6 +374,7 @@ static int netvsc_init_buf(struct hv_device *device,
 	unsigned int buf_size;
 	size_t map_words;
 	int i, ret = 0;
+	void *vaddr;
 
 	/* Get receive buffer area. */
 	buf_size = device_info->recv_sections * device_info->recv_section_size;
@@ -375,6 +410,15 @@ static int netvsc_init_buf(struct hv_device *device,
 		goto cleanup;
 	}
 
+	if (hv_isolation_type_snp()) {
+		vaddr = netvsc_remap_buf(net_device->recv_buf, buf_size);
+		if (!vaddr)
+			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));
@@ -477,6 +521,15 @@ static int netvsc_init_buf(struct hv_device *device,
 		goto cleanup;
 	}
 
+	if (hv_isolation_type_snp()) {
+		vaddr = netvsc_remap_buf(net_device->send_buf, buf_size);
+		if (!vaddr)
+			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));
@@ -767,7 +820,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
 
 	/* Notify the layer above us */
 	if (likely(skb)) {
-		const struct hv_netvsc_packet *packet
+		struct hv_netvsc_packet *packet
 			= (struct hv_netvsc_packet *)skb->cb;
 		u32 send_index = packet->send_buf_index;
 		struct netvsc_stats *tx_stats;
@@ -783,6 +836,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev,
 		tx_stats->bytes += packet->total_bytes;
 		u64_stats_update_end(&tx_stats->syncp);
 
+		netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
 		napi_consume_skb(skb, budget);
 	}
 
@@ -947,6 +1001,82 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 		memset(dest, 0, padding);
 }
 
+void netvsc_dma_unmap(struct hv_device *hv_dev,
+		      struct hv_netvsc_packet *packet)
+{
+	u32 page_count = packet->cp_partial ?
+		packet->page_buf_cnt - packet->rmsg_pgcnt :
+		packet->page_buf_cnt;
+	int i;
+
+	if (!hv_is_isolation_supported())
+		return;
+
+	if (!packet->dma_range)
+		return;
+
+	for (i = 0; i < page_count; i++)
+		dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,
+				 packet->dma_range[i].mapping_size,
+				 DMA_TO_DEVICE);
+
+	kfree(packet->dma_range);
+}
+
+/* netvsc_dma_map - Map swiotlb bounce buffer with data page of
+ * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation
+ * VM.
+ *
+ * In isolation VM, netvsc send buffer has been marked visible to
+ * host and so the data copied to send buffer doesn't need to use
+ * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer()
+ * may not be copied to send buffer and so these pages need to be
+ * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do
+ * that. The pfns in the struct hv_page_buffer need to be converted
+ * to bounce buffer's pfn. The loop here is necessary and so not
+ * use dma_map_sg() here.
+ */
+int netvsc_dma_map(struct hv_device *hv_dev,
+		   struct hv_netvsc_packet *packet,
+		   struct hv_page_buffer *pb)
+{
+	u32 page_count =  packet->cp_partial ?
+		packet->page_buf_cnt - packet->rmsg_pgcnt :
+		packet->page_buf_cnt;
+	dma_addr_t dma;
+	int i;
+
+	if (!hv_is_isolation_supported())
+		return 0;
+
+	packet->dma_range = kcalloc(page_count,
+				    sizeof(*packet->dma_range),
+				    GFP_KERNEL);
+	if (!packet->dma_range)
+		return -ENOMEM;
+
+	for (i = 0; i < page_count; i++) {
+		char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT)
+					 + pb[i].offset);
+		u32 len = pb[i].len;
+
+		dma = dma_map_single(&hv_dev->device, src, len,
+				     DMA_TO_DEVICE);
+		if (dma_mapping_error(&hv_dev->device, dma)) {
+			kfree(packet->dma_range);
+			return -ENOMEM;
+		}
+
+		packet->dma_range[i].dma = dma;
+		packet->dma_range[i].mapping_size = len;
+		pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;
+		pb[i].offset = offset_in_hvpage(dma);
+		pb[i].len = len;
+	}
+
+	return 0;
+}
+
 static inline int netvsc_send_pkt(
 	struct hv_device *device,
 	struct hv_netvsc_packet *packet,
@@ -987,14 +1117,22 @@ static inline int netvsc_send_pkt(
 
 	trace_nvsp_send_pkt(ndev, out_channel, rpkt);
 
+	packet->dma_range = NULL;
 	if (packet->page_buf_cnt) {
 		if (packet->cp_partial)
 			pb += packet->rmsg_pgcnt;
 
+		ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);
+		if (ret)
+			return ret;
+
 		ret = vmbus_sendpacket_pagebuffer(out_channel,
 						  pb, packet->page_buf_cnt,
 						  &nvmsg, sizeof(nvmsg),
 						  req_id);
+
+		if (ret)
+			netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
 	} else {
 		ret = vmbus_sendpacket(out_channel,
 				       &nvmsg, sizeof(nvmsg),
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 983bf362466a..9425fee85aa0 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -361,6 +361,8 @@ static void rndis_filter_receive_response(struct net_device *ndev,
 			}
 		}
 
+		netvsc_dma_unmap(((struct net_device_context *)
+			netdev_priv(ndev))->device_ctx, &request->pkt);
 		complete(&request->wait_event);
 	} else {
 		netdev_err(ndev,
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index babbe19f57e2..90abff664495 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1616,6 +1616,11 @@ struct hyperv_service_callback {
 	void (*callback)(void *context);
 };
 
+struct hv_dma_range {
+	dma_addr_t dma;
+	u32 mapping_size;
+};
+
 #define MAX_SRV_VER	0x7ffffff
 extern bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, u32 buflen,
 				const int *fw_version, int fw_vercnt,
-- 
2.25.1

[Resend RFC PATCH V4 12/13] HV/Storvsc: Add Isolation VM support for storvsc driver

[Tianyu Lan]

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

In Isolation VM, all shared memory with host needs to mark visible
to host via hvcall. vmbus_establish_gpadl() has already done it for
storvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
mpb_desc() still need to handle. Use DMA API to map/umap these
memory during sending/receiving packet and Hyper-V DMA ops callback
will use swiotlb function to allocate bounce buffer and copy data
from/to bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 drivers/scsi/storvsc_drv.c | 68 +++++++++++++++++++++++++++++++++++---
 1 file changed, 63 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 403753929320..cc9cb32f6621 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -21,6 +21,8 @@
 #include <linux/device.h>
 #include <linux/hyperv.h>
 #include <linux/blkdev.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_host.h>
@@ -427,6 +429,8 @@ struct storvsc_cmd_request {
 	u32 payload_sz;
 
 	struct vstor_packet vstor_packet;
+	u32 hvpg_count;
+	struct hv_dma_range *dma_range;
 };
 
 
@@ -509,6 +513,14 @@ struct storvsc_scan_work {
 	u8 tgt_id;
 };
 
+#define storvsc_dma_map(dev, page, offset, size, dir) \
+	dma_map_page(dev, page, offset, size, dir)
+
+#define storvsc_dma_unmap(dev, dma_range, dir)		\
+		dma_unmap_page(dev, dma_range.dma,	\
+			       dma_range.mapping_size,	\
+			       dir ? DMA_FROM_DEVICE : DMA_TO_DEVICE)
+
 static void storvsc_device_scan(struct work_struct *work)
 {
 	struct storvsc_scan_work *wrk;
@@ -1267,6 +1279,7 @@ static void storvsc_on_channel_callback(void *context)
 	struct hv_device *device;
 	struct storvsc_device *stor_device;
 	struct Scsi_Host *shost;
+	int i;
 
 	if (channel->primary_channel != NULL)
 		device = channel->primary_channel->device_obj;
@@ -1321,6 +1334,15 @@ static void storvsc_on_channel_callback(void *context)
 				request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
 			}
 
+			if (request->dma_range) {
+				for (i = 0; i < request->hvpg_count; i++)
+					storvsc_dma_unmap(&device->device,
+						request->dma_range[i],
+						request->vstor_packet.vm_srb.data_in == READ_TYPE);
+
+				kfree(request->dma_range);
+			}
+
 			storvsc_on_receive(stor_device, packet, request);
 			continue;
 		}
@@ -1817,7 +1839,9 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 		unsigned int hvpgoff, hvpfns_to_add;
 		unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
 		unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
+		dma_addr_t dma;
 		u64 hvpfn;
+		u32 size;
 
 		if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
 
@@ -1831,6 +1855,13 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 		payload->range.len = length;
 		payload->range.offset = offset_in_hvpg;
 
+		cmd_request->dma_range = kcalloc(hvpg_count,
+				 sizeof(*cmd_request->dma_range),
+				 GFP_ATOMIC);
+		if (!cmd_request->dma_range) {
+			ret = -ENOMEM;
+			goto free_payload;
+		}
 
 		for (i = 0; sgl != NULL; sgl = sg_next(sgl)) {
 			/*
@@ -1854,9 +1885,29 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 			 * last sgl should be reached at the same time that
 			 * the PFN array is filled.
 			 */
-			while (hvpfns_to_add--)
-				payload->range.pfn_array[i++] =	hvpfn++;
+			while (hvpfns_to_add--) {
+				size = min(HV_HYP_PAGE_SIZE - offset_in_hvpg,
+					   (unsigned long)length);
+				dma = storvsc_dma_map(&dev->device, pfn_to_page(hvpfn++),
+						      offset_in_hvpg, size,
+						      scmnd->sc_data_direction);
+				if (dma_mapping_error(&dev->device, dma)) {
+					ret = -ENOMEM;
+					goto free_dma_range;
+				}
+
+				if (offset_in_hvpg) {
+					payload->range.offset = dma & ~HV_HYP_PAGE_MASK;
+					offset_in_hvpg = 0;
+				}
+
+				cmd_request->dma_range[i].dma = dma;
+				cmd_request->dma_range[i].mapping_size = size;
+				payload->range.pfn_array[i++] = dma >> HV_HYP_PAGE_SHIFT;
+				length -= size;
+			}
 		}
+		cmd_request->hvpg_count = hvpg_count;
 	}
 
 	cmd_request->payload = payload;
@@ -1867,13 +1918,20 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	put_cpu();
 
 	if (ret == -EAGAIN) {
-		if (payload_sz > sizeof(cmd_request->mpb))
-			kfree(payload);
 		/* no more space */
-		return SCSI_MLQUEUE_DEVICE_BUSY;
+		ret = SCSI_MLQUEUE_DEVICE_BUSY;
+		goto free_dma_range;
 	}
 
 	return 0;
+
+free_dma_range:
+	kfree(cmd_request->dma_range);
+
+free_payload:
+	if (payload_sz > sizeof(cmd_request->mpb))
+		kfree(payload);
+	return ret;
 }
 
 static struct scsi_host_template scsi_driver = {
-- 
2.25.1

[Resend RFC PATCH V4 13/13] x86/HV: Not set memory decrypted/encrypted during kexec alloc/free page in IVM

[Tianyu Lan]

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

Hyper-V Isolation VM reuses set_memory_decrypted/encrypted function
and not needs to decrypted/encrypted in arch_kexec_post_alloc(pre_free)
_pages just likes AMD SEV VM. So skip them.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
---
 arch/x86/kernel/machine_kexec_64.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index c078b0d3ab0e..0cadc64b6873 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -26,6 +26,7 @@
 #include <asm/kexec-bzimage64.h>
 #include <asm/setup.h>
 #include <asm/set_memory.h>
+#include <asm/mshyperv.h>
 
 #ifdef CONFIG_ACPI
 /*
@@ -598,7 +599,7 @@ void arch_kexec_unprotect_crashkres(void)
  */
 int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
 {
-	if (sev_active())
+	if (sev_active() || hv_is_isolation_supported())
 		return 0;
 
 	/*
@@ -611,7 +612,7 @@ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
 
 void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages)
 {
-	if (sev_active())
+	if (sev_active() || hv_is_isolation_supported())
 		return;
 
 	/*
-- 
2.25.1

Re: [Resend RFC PATCH V4 13/13] x86/HV: Not set memory decrypted/encrypted during kexec alloc/free page in IVM

[Dave Hansen]

On 7/7/21 8:46 AM, Tianyu Lan wrote:
> @@ -598,7 +599,7 @@ void arch_kexec_unprotect_crashkres(void)
>   */
>  int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
>  {
> -	if (sev_active())
> +	if (sev_active() || hv_is_isolation_supported())
>  		return 0;
>  
>  	/*
> @@ -611,7 +612,7 @@ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
>  
>  void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages)
>  {
> -	if (sev_active())
> +	if (sev_active() || hv_is_isolation_supported())
>  		return;

You might want to take a look through the "protected guest" patches.  I
think this series is touching a few of the same locations that TDX and
recent SEV work touch.

https://lore.kernel.org/lkml/20210618225755.662725-5-sathyanarayanan.kuppuswamy@linux.intel.com/

Re: [Resend RFC PATCH V4 13/13] x86/HV: Not set memory decrypted/encrypted during kexec alloc/free page in IVM

[Tianyu Lan]

Hi Dave:
      Thanks for your review.

On 7/8/2021 12:14 AM, Dave Hansen wrote:
> On 7/7/21 8:46 AM, Tianyu Lan wrote:
>> @@ -598,7 +599,7 @@ void arch_kexec_unprotect_crashkres(void)
>>    */
>>   int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
>>   {
>> -	if (sev_active())
>> +	if (sev_active() || hv_is_isolation_supported())
>>   		return 0;
>>   
>>   	/*
>> @@ -611,7 +612,7 @@ int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp)
>>   
>>   void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages)
>>   {
>> -	if (sev_active())
>> +	if (sev_active() || hv_is_isolation_supported())
>>   		return;
> 
> You might want to take a look through the "protected guest" patches.  I
> think this series is touching a few of the same locations that TDX and
> recent SEV work touch.
> 
> https://lore.kernel.org/lkml/20210618225755.662725-5-sathyanarayanan.kuppuswamy@linux.intel.com/

Thanks for reminder. You are right. There will be a generic API to check 
"proteced guest" type.

[Resend RFC PATCH V4 00/13] 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.

Change since v3:
       - Add interface set_memory_decrypted_map() to decrypt memory and
         map bounce buffer in extra address space 
       - Remove swiotlb remap function and store the remap address
         returned by set_memory_decrypted_map() in swiotlb mem data structure.
       - Introduce hv_set_mem_enc() to make code more readable in the __set_memory_enc_dec().

Change since v2:
       - Remove not UIO driver in Isolation VM patch
       - Use vmap_pfn() to replace ioremap_page_range function in
       order to avoid exposing symbol ioremap_page_range() and
       ioremap_page_range()
       - Call hv set mem host visibility hvcall in set_memory_encrypted/decrypted()
       - Enable swiotlb force mode instead of adding Hyper-V dma map/unmap hook
       - Fix code style

Tianyu Lan (13):
  x86/HV: Initialize GHCB page in Isolation VM
  x86/HV: Initialize shared memory boundary in the Isolation VM.
  x86/HV: Add new hvcall guest address host visibility support
  HV: Mark vmbus ring buffer visible to host in Isolation VM
  HV: Add Write/Read MSR registers via ghcb page
  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/Swiotlb/HV: Add Swiotlb bounce buffer remap function for HV IVM
  HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM
  HV/Netvsc: Add Isolation VM support for netvsc driver
  HV/Storvsc: Add Isolation VM support for storvsc driver
  x86/HV: Not set memory decrypted/encrypted during kexec alloc/free
    page in IVM

 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |  25 +--
 arch/x86/hyperv/ivm.c              | 299 +++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  18 ++
 arch/x86/include/asm/mshyperv.h    |  84 +++++++-
 arch/x86/include/asm/set_memory.h  |   2 +
 arch/x86/include/asm/sev-es.h      |   4 +
 arch/x86/kernel/cpu/mshyperv.c     |   5 +
 arch/x86/kernel/machine_kexec_64.c |   5 +-
 arch/x86/kernel/sev-es-shared.c    |  21 +-
 arch/x86/mm/pat/set_memory.c       |  34 +++-
 arch/x86/xen/pci-swiotlb-xen.c     |   3 +-
 drivers/hv/Kconfig                 |   1 +
 drivers/hv/channel.c               |  48 ++++-
 drivers/hv/connection.c            |  71 ++++++-
 drivers/hv/hv.c                    | 129 +++++++++----
 drivers/hv/hyperv_vmbus.h          |   3 +
 drivers/hv/ring_buffer.c           |  84 ++++++--
 drivers/hv/vmbus_drv.c             |   3 +
 drivers/iommu/hyperv-iommu.c       |  62 ++++++
 drivers/net/hyperv/hyperv_net.h    |   6 +
 drivers/net/hyperv/netvsc.c        | 144 +++++++++++++-
 drivers/net/hyperv/rndis_filter.c  |   2 +
 drivers/scsi/storvsc_drv.c         |  68 ++++++-
 include/asm-generic/hyperv-tlfs.h  |   1 +
 include/asm-generic/mshyperv.h     |  53 ++++-
 include/linux/hyperv.h             |  16 ++
 include/linux/swiotlb.h            |   4 +
 kernel/dma/swiotlb.c               |  11 +-
 29 files changed, 1097 insertions(+), 111 deletions(-)
 create mode 100644 arch/x86/hyperv/ivm.c

-- 
2.25.1