From: Tianyu Lan <Tianyu.Lan@microsoft.com>
Date: Mon, 25 Oct 2021 08:21:08 -0400
Subject: x86/hyperv: Add new hvcall guest address host visibility support
Git-commit: 810a521265023a1d5c6c081ea2d216bc63d422f5
Patch-mainline: v5.16-rc1
References: bsc#1183682
Add new hvcall guest address host visibility support to mark
memory visible to host. Call it inside set_memory_decrypted
/encrypted(). Add HYPERVISOR feature check in the
hv_is_isolation_supported() to optimize in non-virtualization
environment.
Acked-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com
[ wei: fix conflicts with tip ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/hyperv/Makefile | 2
arch/x86/hyperv/hv_init.c | 6 ++
arch/x86/hyperv/ivm.c | 105 +++++++++++++++++++++++++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 17 +++++
arch/x86/include/asm/mshyperv.h | 7 ++
arch/x86/mm/pat/set_memory.c | 23 ++++++--
include/asm-generic/hyperv-tlfs.h | 1
7 files changed, 154 insertions(+), 7 deletions(-)
--- 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
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -603,6 +603,12 @@ EXPORT_SYMBOL_GPL(hv_get_isolation_type)
bool hv_is_isolation_supported(void)
{
+ if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
+ return false;
+
+ if (!hypervisor_is_type(X86_HYPER_MS_HYPERV))
+ return false;
+
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE;
}
--- /dev/null
+++ b/arch/x86/hyperv/ivm.c
@@ -0,0 +1,105 @@
+// 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 encrypted from host and guest
+ * needs to set memory visible to host via hvcall before sharing memory
+ * with host.
+ */
+static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
+ enum hv_mem_host_visibility 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_result_success(hv_status))
+ return 0;
+ else
+ return -EFAULT;
+}
+
+/*
+ * 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.
+ */
+int hv_set_mem_host_visibility(unsigned long kbuffer, int pagecount, bool visible)
+{
+ enum hv_mem_host_visibility visibility = visible ?
+ VMBUS_PAGE_VISIBLE_READ_WRITE : VMBUS_PAGE_NOT_VISIBLE;
+ u64 *pfn_array;
+ int ret = 0;
+ int i, pfn;
+
+ if (!hv_is_isolation_supported() || !hv_hypercall_pg)
+ return 0;
+
+ pfn_array = kmalloc(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((void *)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);
+ if (ret)
+ goto err_free_pfn_array;
+ pfn = 0;
+ }
+ }
+
+ err_free_pfn_array:
+ kfree(pfn_array);
+ return ret;
+}
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -276,6 +276,23 @@ 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 memory host visibility */
+enum hv_mem_host_visibility {
+ VMBUS_PAGE_NOT_VISIBLE = 0,
+ VMBUS_PAGE_VISIBLE_READ_ONLY = 1,
+ VMBUS_PAGE_VISIBLE_READ_WRITE = 3
+};
+
+/* HvCallModifySparseGpaPageHostVisibility hypercall */
+#define HV_MAX_MODIFY_GPA_REP_COUNT ((PAGE_SIZE / sizeof(u64)) - 2)
+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;
+
/*
* Declare the MSR used to setup pages used to communicate with the hypervisor.
*/
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -192,7 +192,7 @@ struct irq_domain *hv_create_pci_msi_dom
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_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
@@ -209,6 +209,11 @@ static inline int hyperv_flush_guest_map
{
return -1;
}
+static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
+ bool visible)
+{
+ return -1;
+}
#endif /* CONFIG_HYPERV */
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -30,6 +30,8 @@
#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"
@@ -1981,15 +1983,15 @@ int set_memory_global(unsigned long addr
__pgprot(_PAGE_GLOBAL), 0);
}
-static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+/*
+ * __set_memory_enc_pgtable() is used for the hypervisors that get
+ * informed about "encryption" status via page tables.
+ */
+static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
{
struct cpa_data cpa;
int ret;
- /* Nothing to do if memory encryption is not active */
- if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
- return 0;
-
/* Should not be working on unaligned addresses */
if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
addr &= PAGE_MASK;
@@ -2024,6 +2026,17 @@ static int __set_memory_enc_dec(unsigned
return ret;
}
+static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
+{
+ if (hv_is_isolation_supported())
+ return hv_set_mem_host_visibility(addr, numpages, !enc);
+
+ if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
+ return __set_memory_enc_pgtable(addr, numpages, enc);
+
+ return 0;
+}
+
int set_memory_encrypted(unsigned long addr, int numpages)
{
return __set_memory_enc_dec(addr, numpages, true);
--- 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