[PATCH v12 06/24] virt: geniezone: Add set_user_memory_region for vm

From: Liju-clr Chen
Date: Tue Jul 30 2024 - 04:30:43 EST


From: Yingshiuan Pan <yingshiuan.pan@xxxxxxxxxxxx>

Direct use of physical memory from VMs is forbidden and designed to be
dictated to the privilege models managed by GenieZone hypervisor for
security reason. With the help of gzvm-ko, the hypervisor would be able
to manipulate memory as objects. And the memory management is highly
integrated with ARM 2-stage translation tables to convert VA to IPA to
PA under proper security measures required by protected VMs.

Signed-off-by: Yingshiuan Pan <yingshiuan.pan@xxxxxxxxxxxx>
Co-developed-by: Jerry Wang <ze-yu.wang@xxxxxxxxxxxx>
Signed-off-by: Jerry Wang <ze-yu.wang@xxxxxxxxxxxx>
Signed-off-by: Yi-De Wu <yi-de.wu@xxxxxxxxxxxx>
Signed-off-by: Liju Chen <liju-clr.chen@xxxxxxxxxxxx>
---
arch/arm64/geniezone/gzvm_arch_common.h | 2 +
arch/arm64/geniezone/vm.c | 9 ++
drivers/virt/geniezone/gzvm_vm.c | 141 ++++++++++++++++++++++++
include/linux/soc/mediatek/gzvm_drv.h | 65 +++++++++++
include/uapi/linux/gzvm.h | 31 ++++++
5 files changed, 248 insertions(+)

diff --git a/arch/arm64/geniezone/gzvm_arch_common.h b/arch/arm64/geniezone/gzvm_arch_common.h
index 60ee5ed2b39f..4250c0f567e7 100644
--- a/arch/arm64/geniezone/gzvm_arch_common.h
+++ b/arch/arm64/geniezone/gzvm_arch_common.h
@@ -11,6 +11,7 @@
enum {
GZVM_FUNC_CREATE_VM = 0,
GZVM_FUNC_DESTROY_VM = 1,
+ GZVM_FUNC_SET_MEMREGION = 4,
GZVM_FUNC_PROBE = 12,
NR_GZVM_FUNC,
};
@@ -23,6 +24,7 @@ enum {

#define MT_HVC_GZVM_CREATE_VM GZVM_HCALL_ID(GZVM_FUNC_CREATE_VM)
#define MT_HVC_GZVM_DESTROY_VM GZVM_HCALL_ID(GZVM_FUNC_DESTROY_VM)
+#define MT_HVC_GZVM_SET_MEMREGION GZVM_HCALL_ID(GZVM_FUNC_SET_MEMREGION)
#define MT_HVC_GZVM_PROBE GZVM_HCALL_ID(GZVM_FUNC_PROBE)

/**
diff --git a/arch/arm64/geniezone/vm.c b/arch/arm64/geniezone/vm.c
index 8ee5490d604a..d4f0aa81d224 100644
--- a/arch/arm64/geniezone/vm.c
+++ b/arch/arm64/geniezone/vm.c
@@ -63,6 +63,15 @@ int gzvm_arch_probe(void)
return 0;
}

+int gzvm_arch_set_memregion(u16 vm_id, size_t buf_size,
+ phys_addr_t region)
+{
+ struct arm_smccc_res res;
+
+ return gzvm_hypcall_wrapper(MT_HVC_GZVM_SET_MEMREGION, vm_id,
+ buf_size, region, 0, 0, 0, 0, &res);
+}
+
/**
* gzvm_arch_create_vm() - create vm
* @vm_type: VM type. Only supports Linux VM now.
diff --git a/drivers/virt/geniezone/gzvm_vm.c b/drivers/virt/geniezone/gzvm_vm.c
index 76722dba6b1f..052ba236dfec 100644
--- a/drivers/virt/geniezone/gzvm_vm.c
+++ b/drivers/virt/geniezone/gzvm_vm.c
@@ -15,6 +15,146 @@
static DEFINE_MUTEX(gzvm_list_lock);
static LIST_HEAD(gzvm_list);

+int gzvm_gfn_to_hva_memslot(struct gzvm_memslot *memslot, u64 gfn,
+ u64 *hva_memslot)
+{
+ u64 offset;
+
+ if (gfn < memslot->base_gfn)
+ return -EINVAL;
+
+ offset = gfn - memslot->base_gfn;
+ *hva_memslot = memslot->userspace_addr + offset * PAGE_SIZE;
+ return 0;
+}
+
+/**
+ * register_memslot_addr_range() - Register memory region to GenieZone
+ * @gzvm: Pointer to struct gzvm
+ * @memslot: Pointer to struct gzvm_memslot
+ *
+ * Return: 0 for success, negative number for error
+ */
+static int
+register_memslot_addr_range(struct gzvm *gzvm, struct gzvm_memslot *memslot)
+{
+ struct gzvm_memory_region_ranges *region;
+ u32 buf_size = PAGE_SIZE * 2;
+ u64 gfn;
+
+ region = alloc_pages_exact(buf_size, GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ region->slot = memslot->slot_id;
+ region->total_pages = memslot->npages;
+ gfn = memslot->base_gfn;
+ region->gpa = PFN_PHYS(gfn);
+
+ if (gzvm_arch_set_memregion(gzvm->vm_id, buf_size,
+ virt_to_phys(region))) {
+ pr_err("Failed to register memregion to hypervisor\n");
+ free_pages_exact(region, buf_size);
+ return -EFAULT;
+ }
+
+ free_pages_exact(region, buf_size);
+ return 0;
+}
+
+/**
+ * memory_region_pre_check() - Preliminary check for userspace memory region
+ * @gzvm: Pointer to struct gzvm.
+ * @mem: Input memory region from user.
+ *
+ * Return: true for check passed, false for invalid input.
+ */
+static bool
+memory_region_pre_check(struct gzvm *gzvm,
+ struct gzvm_userspace_memory_region *mem)
+{
+ if (mem->slot >= GZVM_MAX_MEM_REGION)
+ return false;
+
+ if (!PAGE_ALIGNED(mem->guest_phys_addr) ||
+ !PAGE_ALIGNED(mem->memory_size))
+ return false;
+
+ if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
+ return false;
+
+ if ((mem->memory_size >> PAGE_SHIFT) > GZVM_MEM_MAX_NR_PAGES)
+ return false;
+
+ return true;
+}
+
+/**
+ * gzvm_vm_ioctl_set_memory_region() - Set memory region of guest
+ * @gzvm: Pointer to struct gzvm.
+ * @mem: Input memory region from user.
+ *
+ * Return: 0 for success, negative number for error
+ *
+ * -EXIO - The memslot is out-of-range
+ * -EFAULT - Cannot find corresponding vma
+ * -EINVAL - Region size and VMA size mismatch
+ */
+static int
+gzvm_vm_ioctl_set_memory_region(struct gzvm *gzvm,
+ struct gzvm_userspace_memory_region *mem)
+{
+ struct vm_area_struct *vma;
+ struct gzvm_memslot *memslot;
+ unsigned long size;
+
+ if (memory_region_pre_check(gzvm, mem) != true)
+ return -EINVAL;
+
+ memslot = &gzvm->memslot[mem->slot];
+
+ vma = vma_lookup(gzvm->mm, mem->userspace_addr);
+ if (!vma)
+ return -EFAULT;
+
+ size = vma->vm_end - vma->vm_start;
+ if (size != mem->memory_size)
+ return -EINVAL;
+
+ memslot->base_gfn = __phys_to_pfn(mem->guest_phys_addr);
+ memslot->npages = size >> PAGE_SHIFT;
+ memslot->userspace_addr = mem->userspace_addr;
+ memslot->vma = vma;
+ memslot->flags = mem->flags;
+ memslot->slot_id = mem->slot;
+ return register_memslot_addr_range(gzvm, memslot);
+}
+
+/* gzvm_vm_ioctl() - Ioctl handler of VM FD */
+static long gzvm_vm_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
+{
+ long ret;
+ void __user *argp = (void __user *)arg;
+ struct gzvm *gzvm = filp->private_data;
+
+ switch (ioctl) {
+ case GZVM_SET_USER_MEMORY_REGION: {
+ struct gzvm_userspace_memory_region userspace_mem;
+
+ if (copy_from_user(&userspace_mem, argp, sizeof(userspace_mem)))
+ return -EFAULT;
+
+ ret = gzvm_vm_ioctl_set_memory_region(gzvm, &userspace_mem);
+ break;
+ }
+ default:
+ ret = -ENOTTY;
+ }
+
+ return ret;
+}
+
static void gzvm_destroy_vm(struct gzvm *gzvm)
{
pr_debug("VM-%u is going to be destroyed\n", gzvm->vm_id);
@@ -42,6 +182,7 @@ static int gzvm_vm_release(struct inode *inode, struct file *filp)

static const struct file_operations gzvm_vm_fops = {
.release = gzvm_vm_release,
+ .unlocked_ioctl = gzvm_vm_ioctl,
.llseek = noop_llseek,
};

diff --git a/include/linux/soc/mediatek/gzvm_drv.h b/include/linux/soc/mediatek/gzvm_drv.h
index e7c29c826a7c..3551de8eda1d 100644
--- a/include/linux/soc/mediatek/gzvm_drv.h
+++ b/include/linux/soc/mediatek/gzvm_drv.h
@@ -7,9 +7,16 @@
#define __GZVM_DRV_H__

#include <linux/list.h>
+#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/gzvm.h>

+/*
+ * For the normal physical address, the highest 12 bits should be zero, so we
+ * can mask bit 62 ~ bit 52 to indicate the error physical address
+ */
+#define GZVM_PA_ERR_BAD (0x7ffULL << 52)
+
#define INVALID_VM_ID 0xffff

/*
@@ -23,16 +30,69 @@
#define ERR_NOT_IMPLEMENTED (-27)
#define ERR_FAULT (-40)

+/*
+ * The following data structures are for data transferring between driver and
+ * hypervisor, and they're aligned with hypervisor definitions
+ */
+#define GZVM_MAX_MEM_REGION 10
+
+/**
+ * struct mem_region_addr_range: identical to ffa memory constituent
+ * @address: the base IPA of the constituent memory region, aligned to 4 kiB
+ * @pg_cnt: the number of 4 kiB pages in the constituent memory region
+ * @reserved: reserved for 64bit alignment
+ */
+struct mem_region_addr_range {
+ __u64 address;
+ __u32 pg_cnt;
+ __u32 reserved;
+};
+
+struct gzvm_memory_region_ranges {
+ __u32 slot;
+ __u32 constituent_cnt;
+ __u64 total_pages;
+ __u64 gpa;
+ struct mem_region_addr_range constituents[];
+};
+
+/*
+ * A reasonable and large enough limit for the maximum number of pages a
+ * guest can use.
+ */
+#define GZVM_MEM_MAX_NR_PAGES ((1UL << 31) - 1)
+
+/**
+ * struct gzvm_memslot: VM's memory slot descriptor
+ * @base_gfn: begin of guest page frame
+ * @npages: number of pages this slot covers
+ * @userspace_addr: corresponding userspace va
+ * @vma: vma related to this userspace addr
+ * @flags: define the usage of memory region. Ex. guest memory or
+ * firmware protection
+ * @slot_id: the id is used to identify the memory slot
+ */
+struct gzvm_memslot {
+ u64 base_gfn;
+ unsigned long npages;
+ unsigned long userspace_addr;
+ struct vm_area_struct *vma;
+ u32 flags;
+ u32 slot_id;
+};
+
/**
* struct gzvm: the following data structures are for data transferring between
* driver and hypervisor, and they're aligned with hypervisor definitions.
* @mm: userspace tied to this vm
+ * @memslot: VM's memory slot descriptor
* @lock: lock for list_add
* @vm_list: list head for vm list
* @vm_id: vm id
*/
struct gzvm {
struct mm_struct *mm;
+ struct gzvm_memslot memslot[GZVM_MAX_MEM_REGION];
struct mutex lock;
struct list_head vm_list;
u16 vm_id;
@@ -46,7 +106,12 @@ void gzvm_destroy_all_vms(void);

/* arch-dependant functions */
int gzvm_arch_probe(void);
+int gzvm_arch_set_memregion(u16 vm_id, size_t buf_size,
+ phys_addr_t region);
int gzvm_arch_create_vm(unsigned long vm_type);
int gzvm_arch_destroy_vm(u16 vm_id);

+int gzvm_gfn_to_hva_memslot(struct gzvm_memslot *memslot, u64 gfn,
+ u64 *hva_memslot);
+
#endif /* __GZVM_DRV_H__ */
diff --git a/include/uapi/linux/gzvm.h b/include/uapi/linux/gzvm.h
index c26c7720fab7..59c0f790b2e6 100644
--- a/include/uapi/linux/gzvm.h
+++ b/include/uapi/linux/gzvm.h
@@ -22,4 +22,35 @@
/* ioctls for /dev/gzvm fds */
#define GZVM_CREATE_VM _IO(GZVM_IOC_MAGIC, 0x01) /* Returns a Geniezone VM fd */

+/* ioctls for VM fds */
+/* for GZVM_SET_MEMORY_REGION */
+struct gzvm_memory_region {
+ __u32 slot;
+ __u32 flags;
+ __u64 guest_phys_addr;
+ __u64 memory_size; /* bytes */
+};
+
+#define GZVM_SET_MEMORY_REGION _IOW(GZVM_IOC_MAGIC, 0x40, \
+ struct gzvm_memory_region)
+
+/**
+ * struct gzvm_userspace_memory_region: gzvm userspace memory region descriptor
+ * @slot: memory slot
+ * @flags: describe the usage of userspace memory region
+ * @guest_phys_addr: guest vm's physical address
+ * @memory_size: memory size in bytes
+ * @userspace_addr: start of the userspace allocated memory
+ */
+struct gzvm_userspace_memory_region {
+ __u32 slot;
+ __u32 flags;
+ __u64 guest_phys_addr;
+ __u64 memory_size;
+ __u64 userspace_addr;
+};
+
+#define GZVM_SET_USER_MEMORY_REGION _IOW(GZVM_IOC_MAGIC, 0x46, \
+ struct gzvm_userspace_memory_region)
+
#endif /* __GZVM_H__ */
--
2.18.0