On 5/11/2025 2:25 AM, ALOK TIWARI wrote:
On 06-05-2025 14:19, Naman Jain wrote:
Provide an interface for Virtual Machine Monitor like OpenVMM and its
use as OpenHCL paravisor to control VTL0 (Virtual trust Level).
Expose devices and support IOCTLs for features like VTL creation,
VTL0 memory management, context switch, making hypercalls,
mapping VTL0 address space to VTL2 userspace, getting new VMBus
messages and channel events in VTL2 etc.
Co-developed-by: Roman Kisel <rom...@linux.microsoft.com>
Signed-off-by: Roman Kisel <rom...@linux.microsoft.com>
Co-developed-by: Saurabh Sengar <ssen...@linux.microsoft.com>
Signed-off-by: Saurabh Sengar <ssen...@linux.microsoft.com>
Signed-off-by: Naman Jain <namj...@linux.microsoft.com>
---
OpenVMM : https://urldefense.com/v3/__https://openvmm.dev/guide/__;!!
ACWV5N9M2RV99hQ!
JP9UlleLto2qc_MQzB8ehw1vxtg1wE6rkxawFxyrIWJPPUOdoUk5fpa89l-
uhlMNKAdgnWdKXhj5g1AEuVZImYkjDA$
---
drivers/hv/Kconfig | 20 +
drivers/hv/Makefile | 3 +
drivers/hv/hv.c | 2 +
drivers/hv/hyperv_vmbus.h | 1 +
drivers/hv/mshv_vtl.h | 52 ++
drivers/hv/mshv_vtl_main.c | 1749 +++++++++++++++++++++++++++++++++++
drivers/hv/vmbus_drv.c | 3 +-
include/hyperv/hvgdk_mini.h | 81 ++
include/hyperv/hvhdk.h | 1 +
include/uapi/linux/mshv.h | 83 ++
10 files changed, 1994 insertions(+), 1 deletion(-)
create mode 100644 drivers/hv/mshv_vtl.h
create mode 100644 drivers/hv/mshv_vtl_main.c
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 6c1416167bd2..57dcfcb69b88 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -72,4 +72,24 @@ config MSHV_ROOT
If unsure, say N.
+config MSHV_VTL
+ bool "Microsoft Hyper-V VTL driver"
+ depends on HYPERV && X86_64
+ depends on TRANSPARENT_HUGEPAGE
+ depends on OF
+ # MTRRs are not per-VTL and are controlled by VTL0, so don't look
at or mutate them.
# MTRRs are controlled by VTL0, and are not specific to individual VTLs.
# Therefore, do not attempt to access or modify MTRRs here.
ACK.
+ depends on !MTRR
+ select CPUMASK_OFFSTACK
+ select HYPERV_VTL_MODE
+ default n
+ help
+ Select this option to enable Hyper-V VTL driver support.
+ This driver provides interfaces for Virtual Machine Manager
(VMM) running in VTL2
+ userspace to create VTLs and partitions, setup and manage VTL0
memory and
+ allow userspace to make direct hypercalls. This also allows to
map VTL0's address
+ space to a usermode process in VTL2 and supports getting new
VMBus messages and channel
+ events in VTL2.
<snip>
+
+struct mshv_vtl_run {
+ u32 cancel;
+ u32 vtl_ret_action_size;
+ u32 pad[2];
+ char exit_message[MSHV_MAX_RUN_MSG_SIZE];
+ union {
+ struct mshv_vtl_cpu_context cpu_context;
+
+ /*
+ * Reserving room for the cpu context to grow and be
+ * able to maintain compat with user mode.
here compat, sound like typo to compact.
To improve clarity and ensure correctness
"Reserving room for the cpu context to grow and to maintain
compatibility with user mode."
ACK.
+ */
+ char reserved[1024];
+ };
+ char vtl_ret_actions[MSHV_MAX_RUN_MSG_SIZE];
+};
+
+#endif /* _MSHV_VTL_H */
diff --git a/drivers/hv/mshv_vtl_main.c b/drivers/hv/mshv_vtl_main.c
new file mode 100644
index 000000000000..95db29472fc8
--- /dev/null
+++ b/drivers/hv/mshv_vtl_main.c
@@ -0,0 +1,1749 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Microsoft Corporation.
<snip>
+
+static int hv_vtl_setup_synic(void)
+{
+ int ret;
+
+ /* Use our isr to first filter out packets destined for userspace */
+ hv_setup_vmbus_handler(mshv_vtl_vmbus_isr);
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vtl:online",
+ mshv_vtl_alloc_context, NULL);
+ if (ret < 0) {
+ hv_remove_vmbus_handler();
+ return ret;
+ }
+
+ mshv_vtl_cpuhp_online = ret;
a '\n' before return
ACK.
+ return 0;
+}
+
+static void hv_vtl_remove_synic(void)
+{
+ hv_remove_vmbus_handler();
+ cpuhp_remove_state(mshv_vtl_cpuhp_online);
+}
+
+static int vtl_get_vp_registers(u16 count,
+ struct hv_register_assoc *registers)
+{
+ union hv_input_vtl input_vtl;
+
+ input_vtl.as_uint8 = 0;
+ input_vtl.use_target_vtl = 1;
a '\n' before return, pleas consider this for other place also
ACK. Done at other places too in the file.
+ return hv_call_get_vp_registers(HV_VP_INDEX_SELF,
HV_PARTITION_ID_SELF,
+ count, input_vtl, registers);
+}
+
+static int vtl_set_vp_registers(u16 count,
+ struct hv_register_assoc *registers)
+{
+ union hv_input_vtl input_vtl;
+
+ input_vtl.as_uint8 = 0;
+ input_vtl.use_target_vtl = 1;
+ return hv_call_set_vp_registers(HV_VP_INDEX_SELF,
HV_PARTITION_ID_SELF,
+ count, input_vtl, registers);
+}
+
+static int mshv_vtl_ioctl_add_vtl0_mem(struct mshv_vtl *vtl, void
__user *arg)
+{
+ struct mshv_vtl_ram_disposition vtl0_mem;
+ struct dev_pagemap *pgmap;
+ void *addr;
+
+ if (copy_from_user(&vtl0_mem, arg, sizeof(vtl0_mem)))
+ return -EFAULT;
+
+ if (vtl0_mem.last_pfn <= vtl0_mem.start_pfn) {
+ dev_err(vtl->module_dev, "range start pfn (%llx) > end pfn
(%llx)\n",
+ vtl0_mem.start_pfn, vtl0_mem.last_pfn);
+ return -EFAULT;
+ }
+
+ pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
+ if (!pgmap)
+ return -ENOMEM;
+
+ pgmap->ranges[0].start = PFN_PHYS(vtl0_mem.start_pfn);
+ pgmap->ranges[0].end = PFN_PHYS(vtl0_mem.last_pfn) - 1;
+ pgmap->nr_range = 1;
+ pgmap->type = MEMORY_DEVICE_GENERIC;
+
+ /*
+ * Determine the highest page order that can be used for the range.
+ * This works best when the range is aligned; i.e. start and length.
"can be used for the given memory range."
Replaced "range" with "given memory range" to clarify that we are
talking about the memory range of the VTL0 memory.
Reworded "start and length" -> "both the start and the length"
ACK.
+ */
+ pgmap->vmemmap_shift = count_trailing_zeros(vtl0_mem.start_pfn |
vtl0_mem.last_pfn);
+ dev_dbg(vtl->module_dev,
+ "Add VTL0 memory: start: 0x%llx, end_pfn: 0x%llx, page order:
%lu\n",
+ vtl0_mem.start_pfn, vtl0_mem.last_pfn, pgmap->vmemmap_shift);
+
+ addr = devm_memremap_pages(mem_dev, pgmap);
+ if (IS_ERR(addr)) {
+ dev_err(vtl->module_dev, "devm_memremap_pages error: %ld\n",
PTR_ERR(addr));
+ kfree(pgmap);
+ return -EFAULT;
+ }
<snip>
+ return 0;
+}
+
+static int mshv_vtl_set_reg(struct hv_register_assoc *regs)
+{
+ u64 reg64;
+ enum hv_register_name gpr_name;
+
+ gpr_name = regs->name;
+ reg64 = regs->value.reg64;
+
+ switch (gpr_name) {
+ case HV_X64_REGISTER_DR0:
+ native_set_debugreg(0, reg64);
+ break;
+ case HV_X64_REGISTER_DR1:
+ native_set_debugreg(1, reg64);
+ break;
+ case HV_X64_REGISTER_DR2:
+ native_set_debugreg(2, reg64);
+ break;
+ case HV_X64_REGISTER_DR3:
+ native_set_debugreg(3, reg64);
+ break;
+ case HV_X64_REGISTER_DR6:
+ if (!mshv_vsm_capabilities.dr6_shared)
+ goto hypercall;
+ native_set_debugreg(6, reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_CAP:
+ wrmsrl(MSR_MTRRcap, reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_DEF_TYPE:
+ wrmsrl(MSR_MTRRdefType, reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE0:
+ wrmsrl(MTRRphysBase_MSR(0), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE1:
+ wrmsrl(MTRRphysBase_MSR(1), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE2:
+ wrmsrl(MTRRphysBase_MSR(2), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE3:
+ wrmsrl(MTRRphysBase_MSR(3), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE4:
+ wrmsrl(MTRRphysBase_MSR(4), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE5:
+ wrmsrl(MTRRphysBase_MSR(5), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE6:
+ wrmsrl(MTRRphysBase_MSR(6), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE7:
+ wrmsrl(MTRRphysBase_MSR(7), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE8:
+ wrmsrl(MTRRphysBase_MSR(8), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASE9:
+ wrmsrl(MTRRphysBase_MSR(9), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASEA:
+ wrmsrl(MTRRphysBase_MSR(0xa), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASEB:
+ wrmsrl(MTRRphysBase_MSR(0xb), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASEC:
+ wrmsrl(MTRRphysBase_MSR(0xc), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASED:
+ wrmsrl(MTRRphysBase_MSR(0xd), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASEE:
+ wrmsrl(MTRRphysBase_MSR(0xe), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_BASEF:
+ wrmsrl(MTRRphysBase_MSR(0xf), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK0:
+ wrmsrl(MTRRphysMask_MSR(0), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK1:
+ wrmsrl(MTRRphysMask_MSR(1), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK2:
+ wrmsrl(MTRRphysMask_MSR(2), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK3:
+ wrmsrl(MTRRphysMask_MSR(3), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK4:
+ wrmsrl(MTRRphysMask_MSR(4), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK5:
+ wrmsrl(MTRRphysMask_MSR(5), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK6:
+ wrmsrl(MTRRphysMask_MSR(6), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK7:
+ wrmsrl(MTRRphysMask_MSR(7), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK8:
+ wrmsrl(MTRRphysMask_MSR(8), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASK9:
+ wrmsrl(MTRRphysMask_MSR(9), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKA:
+ wrmsrl(MTRRphysMask_MSR(0xa), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKB:
+ wrmsrl(MTRRphysMask_MSR(0xa), reg64);
is this typo or intentional 0xa -> 0xb ?
Thanks for catching this. This must be a typo. Corrected it.
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKC:
+ wrmsrl(MTRRphysMask_MSR(0xc), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKD:
+ wrmsrl(MTRRphysMask_MSR(0xd), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKE:
+ wrmsrl(MTRRphysMask_MSR(0xe), reg64);
+ break;
+ case HV_X64_REGISTER_MSR_MTRR_PHYS_MASKF:
+ wrmsrl(MTRRphysMask_MSR(0xf), reg64);
<snip>
+static struct miscdevice mshv_vtl_sint_dev = {
+ .name = "mshv_sint",
+ .fops = &mshv_vtl_sint_ops,
+ .mode = 0600,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+static int mshv_vtl_hvcall_open(struct inode *node, struct file *f)
+{
+ struct miscdevice *dev = f->private_data;
+ struct mshv_vtl_hvcall_fd *fd;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ fd = vzalloc(sizeof(*fd));
+ if (!fd)
+ return -ENOMEM;
if (!fd) {
f->private_data = NULL;
return -ENOMEM;
}
Explicitly set to NULL to (avoid accidental use)
it can avoids potential issues in later functions that may attempt to
access it. what is your view here ?
Makes sense. Will change it.
+ fd->dev = dev;
+ mutex_init(&fd->init_mutex);
+
+ f->private_data = fd;
Assign immediately after allocation ensures a consistent state and sequence
f->private_data = fd;
fd->dev = dev;
mutex_init(&fd->init_mutex);
Done
+
+ return 0;
+}
+
+static int mshv_vtl_hvcall_release(struct inode *node, struct file *f)
+{
+ struct mshv_vtl_hvcall_fd *fd;
+
+ fd = f->private_data;
+ f->private_data = NULL;
+ vfree(fd);
what about ?
if (fd) {
vfree(fd);
f->private_data = NULL;
}
adding a check will improves readability and robustness.
This seems better. Will change it.
+
+ return 0;
+}
+
+static int mshv_vtl_hvcall_setup(struct mshv_vtl_hvcall_fd *fd,
+ struct mshv_vtl_hvcall_setup __user *hvcall_setup_user)
+{
+ int ret = 0;
+ struct mshv_vtl_hvcall_setup hvcall_setup;
+
+ mutex_lock(&fd->init_mutex);
+
+ if (fd->allow_map_intialized) {
+ dev_err(fd->dev->this_device,
+ "Hypercall allow map has already been set, pid %d\n",
+ current->pid);
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ if (copy_from_user(&hvcall_setup, hvcall_setup_user,
+ sizeof(struct mshv_vtl_hvcall_setup))) {
+ ret = -EFAULT;
+ goto exit;
+ }
+ if (hvcall_setup.bitmap_size > ARRAY_SIZE(fd->allow_bitmap)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+ if (copy_from_user(&fd->allow_bitmap,
+ (void __user *)hvcall_setup.allow_bitmap_ptr,
+ hvcall_setup.bitmap_size)) {
+ ret = -EFAULT;
+ goto exit;
+ }
+
+ dev_info(fd->dev->this_device, "Hypercall allow map has been set,
pid %d\n",
+ current->pid);
+ fd->allow_map_intialized = true;
+
+exit:
+
no need \n here
ACKed.
+ mutex_unlock(&fd->init_mutex);
+
+ return ret;
+}
+
+static bool mshv_vtl_hvcall_is_allowed(struct mshv_vtl_hvcall_fd *fd,
u16 call_code)
+{
+ u8 bits_per_item = 8 * sizeof(fd->allow_bitmap[0]);
+ u16 item_index = call_code / bits_per_item;
+ u64 mask = 1ULL << (call_code % bits_per_item);
+
+ return fd->allow_bitmap[item_index] & mask;
+}
+
+static int mshv_vtl_hvcall_call(struct mshv_vtl_hvcall_fd *fd,
+ struct mshv_vtl_hvcall __user *hvcall_user)
+{
+ struct mshv_vtl_hvcall hvcall;
+ unsigned long flags;
+ void *in, *out;
+
+ if (copy_from_user(&hvcall, hvcall_user, sizeof(struct
mshv_vtl_hvcall)))
+ return -EFAULT;
+ if (hvcall.input_size > HV_HYP_PAGE_SIZE)
+ return -EINVAL;
+ if (hvcall.output_size > HV_HYP_PAGE_SIZE)
+ return -EINVAL;
+
+ /*
+ * By default, all hypercalls are not allowed.
+ * The user mode code has to set up the allow bitmap once.
+ */
+
+ if (!mshv_vtl_hvcall_is_allowed(fd, hvcall.control & 0xFFFF)) {
+ dev_err(fd->dev->this_device,
+ "Hypercall with control data %#llx isn't allowed\n",
+ hvcall.control);
+ return -EPERM;
+ }
+
+ local_irq_save(flags);
+ in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ out = *this_cpu_ptr(hyperv_pcpu_output_arg);
+
+ if (copy_from_user(in, (void __user *)hvcall.input_ptr,
hvcall.input_size)) {
+ local_irq_restore(flags);
+ return -EFAULT;
+ }
+
+ hvcall.status = hv_do_hypercall(hvcall.control, in, out);
+
+ if (copy_to_user((void __user *)hvcall.output_ptr, out,
hvcall.output_size)) {
+ local_irq_restore(flags);
+ return -EFAULT;
+ }
+ local_irq_restore(flags);
+
+ return put_user(hvcall.status, &hvcall_user->status);
+}
+
+static long mshv_vtl_hvcall_ioctl(struct file *f, unsigned int cmd,
unsigned long arg)
+{
+ struct mshv_vtl_hvcall_fd *fd = f->private_data;
+
+ switch (cmd) {
+ case MSHV_HVCALL_SETUP:
+ return mshv_vtl_hvcall_setup(fd, (struct
mshv_vtl_hvcall_setup __user *)arg);
+ case MSHV_HVCALL:
+ return mshv_vtl_hvcall_call(fd, (struct mshv_vtl_hvcall
__user *)arg);
+ default:
+ break;
+ }
+
+ return -ENOIOCTLCMD;
+}
+
+static const struct file_operations mshv_vtl_hvcall_file_ops = {
+ .owner = THIS_MODULE,
+ .open = mshv_vtl_hvcall_open,
+ .release = mshv_vtl_hvcall_release,
+ .unlocked_ioctl = mshv_vtl_hvcall_ioctl,
+};
+
+static struct miscdevice mshv_vtl_hvcall = {
+ .name = "mshv_hvcall",
+ .nodename = "mshv_hvcall",
+ .fops = &mshv_vtl_hvcall_file_ops,
+ .mode = 0600,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+static int mshv_vtl_low_open(struct inode *inodep, struct file *filp)
+{
+ pid_t pid = task_pid_vnr(current);
+ uid_t uid = current_uid().val;
+ int ret = 0;
+
+ pr_debug("%s: Opening VTL low, task group %d, uid %d\n",
__func__, pid, uid);
+
+ if (capable(CAP_SYS_ADMIN)) {
+ filp->private_data = inodep;
+ } else {
+ pr_err("%s: VTL low open failed: CAP_SYS_ADMIN required. task
group %d, uid %d",
+ __func__, pid, uid);
+ ret = -EPERM;
+ }
+
+ return ret;
+}
+
+static bool can_fault(struct vm_fault *vmf, unsigned long size, pfn_t
*pfn)
+{
+ unsigned long mask = size - 1;
+ unsigned long start = vmf->address & ~mask;
+ unsigned long end = start + size;
+ bool valid;
valid is descriptive, but is_valid would be more explicit as a boolean
flag.
Thanks, noted.
+
+ valid = (vmf->address & mask) == ((vmf->pgoff << PAGE_SHIFT) &
mask) &&
+ start >= vmf->vma->vm_start &&
+ end <= vmf->vma->vm_end;
+
+ if (valid)
+ *pfn = __pfn_to_pfn_t(vmf->pgoff & ~(mask >> PAGE_SHIFT),
PFN_DEV | PFN_MAP);
+
+ return valid;
+}
+
+static vm_fault_t mshv_vtl_low_huge_fault(struct vm_fault *vmf,
unsigned int order)
+{
+ pfn_t pfn;
+ int ret = VM_FAULT_FALLBACK;
+
+ switch (order) {
+ case 0:
+ pfn = __pfn_to_pfn_t(vmf->pgoff, PFN_DEV | PFN_MAP);
+ return vmf_insert_mixed(vmf->vma, vmf->address, pfn);
+
+ case PMD_ORDER:
+ if (can_fault(vmf, PMD_SIZE, &pfn))
+ ret = vmf_insert_pfn_pmd(vmf, pfn, vmf->flags &
FAULT_FLAG_WRITE);
+ return ret;
+
+ case PUD_ORDER:
+ if (can_fault(vmf, PUD_SIZE, &pfn))
+ ret = vmf_insert_pfn_pud(vmf, pfn, vmf->flags &
FAULT_FLAG_WRITE);
+ return ret;
+
+ default:
+ return VM_FAULT_SIGBUS;
+ }
+}
+
+static vm_fault_t mshv_vtl_low_fault(struct vm_fault *vmf)
+{
+ return mshv_vtl_low_huge_fault(vmf, 0);
+}
+
+static const struct vm_operations_struct mshv_vtl_low_vm_ops = {
+ .fault = mshv_vtl_low_fault,
+ .huge_fault = mshv_vtl_low_huge_fault,
+};
+
+static int mshv_vtl_low_mmap(struct file *filp, struct vm_area_struct
*vma)
+{
+ vma->vm_ops = &mshv_vtl_low_vm_ops;
+ vm_flags_set(vma, VM_HUGEPAGE | VM_MIXEDMAP);
+ return 0;
+}
+
+static const struct file_operations mshv_vtl_low_file_ops = {
+ .owner = THIS_MODULE,
+ .open = mshv_vtl_low_open,
+ .mmap = mshv_vtl_low_mmap,
+};
+
+static struct miscdevice mshv_vtl_low = {
+ .name = "mshv_vtl_low",
+ .nodename = "mshv_vtl_low",
+ .fops = &mshv_vtl_low_file_ops,
+ .mode = 0600,
+ .minor = MISC_DYNAMIC_MINOR,
+};
+
+static int __init mshv_vtl_init(void)
+{
+ int ret;
+ struct device *dev = mshv_dev.this_device;
+
+ /*
+ * This creates /dev/mshv which provides functionality to create
VTLs and partitions.
+ */
+ ret = misc_register(&mshv_dev);
+ if (ret) {
+ dev_err(dev, "mshv device register failed: %d\n", ret);
+ goto free_dev;
+ }
+
+ tasklet_init(&msg_dpc, mshv_vtl_sint_on_msg_dpc, 0);
+ init_waitqueue_head(&fd_wait_queue);
+
+ if (mshv_vtl_get_vsm_regs()) {
+ dev_emerg(dev, "Unable to get VSM capabilities !!\n");
+ ret = -ENODEV;
+ goto free_dev;
+ }
+ if (mshv_vtl_configure_vsm_partition(dev)) {
+ dev_emerg(dev, "VSM configuration failed !!\n");
+ ret = -ENODEV;
+ goto free_dev;
+ }
+
+ ret = hv_vtl_setup_synic();
+ if (ret)
+ goto free_dev;
+
+ /*
+ * mshv_sint device adds VMBus relay ioctl support.
+ * This provides a channel for VTL0 to communicate with VTL2.
+ */
+ ret = misc_register(&mshv_vtl_sint_dev);
+ if (ret)
+ goto free_synic;
+
+ /*
+ * mshv_hvcall device adds interface to enable userspace for
direct hypercalls support.
+ */
+ ret = misc_register(&mshv_vtl_hvcall);
+ if (ret)
+ goto free_sint;
+
+ /*
+ * mshv_vtl_low device is used to map VTL0 address space to a
user-mode process in VLT2.
typo VLT2 -> VTL2
ACKed.
+ * It implements mmap() to allow a user-mode process in VTL2 to
map to the address of VTL0.
+ */
+ ret = misc_register(&mshv_vtl_low);
+ if (ret)
+ goto free_hvcall;
+
+ /*
+ * "mshv vtl mem dev" device is later used to setup VTL0 memory.
+ */
+ mem_dev = kzalloc(sizeof(*mem_dev), GFP_KERNEL);
+ if (!mem_dev) {
+ ret = -ENOMEM;
+ goto free_low;
+ }
+
+ mutex_init(&mshv_vtl_poll_file_lock);
+
+ device_initialize(mem_dev);
+ dev_set_name(mem_dev, "mshv vtl mem dev");
+ ret = device_add(mem_dev);
+ if (ret) {
+ dev_err(dev, "mshv vtl mem dev add: %d\n", ret);
+ goto free_mem;
+ }
+
+ return 0;
+
+free_mem:
+ kfree(mem_dev);
+free_low:
+ misc_deregister(&mshv_vtl_low);
+free_hvcall:
+ misc_deregister(&mshv_vtl_hvcall);
+free_sint:
<snip>
*/
+/* Structure definitions, macros and IOCTLs for mshv_vtl */
+
+#define MSHV_CAP_CORE_API_STABLE 0x0
+#define MSHV_CAP_REGISTER_PAGE 0x1
+#define MSHV_CAP_VTL_RETURN_ACTION 0x2
+#define MSHV_CAP_DR6_SHARED 0x3
+#define MSHV_MAX_RUN_MSG_SIZE 256
+
+#define MSHV_VP_MAX_REGISTERS 128
+
+struct mshv_vp_registers {
+ __u32 count; /* at most MSHV_VP_MAX_REGISTERS */
+ __u32 padding;
padding -> reserved?
reserved(reserved or reserved1, reserved2) is more commonly used in
structures that may evolve to include additional field
__u32 reserved; /* Reserved for alignment or future use */
I don't have a strong opinion on this, but will change this.
+ __u64 regs_ptr; /* pointer to struct hv_register_assoc */
+};
+
+struct mshv_vtl_set_eventfd {
+ __s32 fd;
+ __u32 flag;
+};
+
+struct mshv_vtl_signal_event {
+ __u32 connection_id;
+ __u32 flag;
+};
+
+struct mshv_vtl_sint_post_msg {
+ __u64 message_type;
+ __u32 connection_id;
+ __u32 payload_size;
do we have max limit for payload ? if yes
__u32 payload_size; /* Must not exceed MSHV_VTL_MAX_PAYLOAD_SIZE */
HV_MESSAGE_PAYLOAD_BYTE_COUNT, is this max payload size ?
No, this is the limit: HV_MESSAGE_PAYLOAD_BYTE_COUNT
Will add the comment.
+ __u64 payload_ptr; /* pointer to message payload (bytes) */
+};
+
+struct mshv_vtl_ram_disposition {
+ __u64 start_pfn;
+ __u64 last_pfn;
+};
+
+struct mshv_vtl_set_poll_file {
+ __u32 cpu;
+ __u32 fd;
+};
+
+struct mshv_vtl_hvcall_setup {
+ __u64 bitmap_size;
+ __u64 allow_bitmap_ptr; /* pointer to __u64 */
+};
+
+struct mshv_vtl_hvcall {
+ __u64 control;
+ __u64 input_size;
+ __u64 input_ptr; /* pointer to input struct */
+ /* output */
+ __u64 status;
+ __u64 output_size;
+ __u64 output_ptr; /* pointer to output struct */
+};
this /* output */ is ambiguous. can we provide all description or non(as
name it self-explanatory) for better consistency and clarity
struct mshv_vtl_hvcall {
__u64 control; /* Hypercall control code */
__u64 input_size; /* Size of the input data */
__u64 input_ptr; /* Pointer to the input struct */
__u64 status; /* Status of the hypercall (output) */
__u64 output_size; /* Size of the output data */
__u64 output_ptr; /* Pointer to the output struct */
};
Will change it. Thanks.
+
+struct mshv_sint_mask {
+ __u8 mask;
+ __u8 reserved[7];
+};
+
+/* /dev/mshv device IOCTL */
+#define MSHV_CHECK_EXTENSION _IOW(MSHV_IOCTL, 0x00, __u32)
+
Thanks,
Alok
Thanks Alok for reviewing the code and suggesting improvements.
I'll take care of them in the next version.
Regards,
Naman
