[RFC PATCH 13/18] virt/mshv: install intercept ioctl

From: Nuno Das Neves
Date: Fri Nov 20 2020 - 19:31:36 EST

Introduce ioctl for configuring intercept messages from a guest partition.

Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
---
Documentation/virt/mshv/api.rst | 9 +++++
arch/x86/include/uapi/asm/hyperv-tlfs.h | 43 ++++++++++++++++++++++
include/asm-generic/hyperv-tlfs.h | 8 ++++
include/uapi/linux/mshv.h | 7 ++++
virt/mshv/mshv_main.c | 49 ++++++++++++++++++++++++-
5 files changed, 115 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/mshv/api.rst b/Documentation/virt/mshv/api.rst
index f525c81f2bdd..95ec77dc73f0 100644
--- a/Documentation/virt/mshv/api.rst
+++ b/Documentation/virt/mshv/api.rst
@@ -120,4 +120,13 @@ This ioctl will fail on any vp that's already running (not suspended).

Information about the intercept is returned in the hv_message struct.

+3.7 MSHV_INSTALL_INTERCEPT
+--------------------------
+:Type: partition ioctl
+:Parameters: struct mshv_install_intercept
+:Returns: 0 on success
+
+Enable and configure different types of intercepts. Intercepts are events in a
+guest partition that will suspend the guest vp and send a message to the root
+partition (returned from MSHV_RUN_VP).

diff --git a/arch/x86/include/uapi/asm/hyperv-tlfs.h b/arch/x86/include/uapi/asm/hyperv-tlfs.h
index c6a27053f791..28917301b6df 100644
--- a/arch/x86/include/uapi/asm/hyperv-tlfs.h
+++ b/arch/x86/include/uapi/asm/hyperv-tlfs.h
@@ -986,4 +986,47 @@ struct hv_x64_apic_eoi_message {
__u32 interrupt_vector;
};

+enum hv_intercept_type {
+ HV_INTERCEPT_TYPE_X64_IO_PORT = 0X00000000,
+ HV_INTERCEPT_TYPE_X64_MSR = 0X00000001,
+ HV_INTERCEPT_TYPE_X64_CPUID = 0X00000002,
+ HV_INTERCEPT_TYPE_EXCEPTION = 0X00000003,
+ HV_INTERCEPT_TYPE_REGISTER = 0X00000004,
+ HV_INTERCEPT_TYPE_MMIO = 0X00000005,
+ HV_INTERCEPT_TYPE_X64_GLOBAL_CPUID = 0X00000006,
+ HV_INTERCEPT_TYPE_X64_APIC_SMI = 0X00000007,
+ HV_INTERCEPT_TYPE_HYPERCALL = 0X00000008,
+ HV_INTERCEPT_TYPE_X64_APIC_INIT_SIPI = 0X00000009,
+ HV_INTERCEPT_MC_UPDATE_PATCH_LEVEL_MSR_READ = 0X0000000A,
+ HV_INTERCEPT_TYPE_X64_APIC_WRITE = 0X0000000B,
+ HV_INTERCEPT_TYPE_MAX,
+ HV_INTERCEPT_TYPE_INVALID = 0XFFFFFFFF,
+};
+
+union hv_intercept_parameters {
+ __u64 as_uint64;
+
+ /* hv_intercept_type_x64_io_port */
+ __u16 io_port;
+
+ /* hv_intercept_type_x64_cpuid */
+ __u32 cpuid_index;
+
+ /* hv_intercept_type_x64_apic_write */
+ __u32 apic_write_mask;
+
+ /* hv_intercept_type_exception */
+ __u16 exception_vector;
+
+ /* N.B. Other intercept types do not have any parameters. */
+};
+
+/* Access types for the install intercept hypercall parameter */
+#define HV_INTERCEPT_ACCESS_MASK_NONE 0x00
+#define HV_INTERCEPT_ACCESS_MASK_READ 0X01
+#define HV_INTERCEPT_ACCESS_MASK_WRITE 0x02
+#define HV_INTERCEPT_ACCESS_MASK_EXECUTE 0x04
+
+
+
#endif
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index e0185c3872a9..93571bbab3a6 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -151,6 +151,7 @@ struct ms_hyperv_tsc_page {
#define HVCALL_WITHDRAW_MEMORY 0x0049
#define HVCALL_MAP_GPA_PAGES 0x004b
#define HVCALL_UNMAP_GPA_PAGES 0x004c
+#define HVCALL_INSTALL_INTERCEPT 0x004d
#define HVCALL_CREATE_VP 0x004e
#define HVCALL_GET_VP_REGISTERS 0x0050
#define HVCALL_SET_VP_REGISTERS 0x0051
@@ -777,4 +778,11 @@ struct hv_unmap_gpa_pages {
u32 unmap_flags;
};

+struct hv_install_intercept {
+ u64 partition_id;
+ u32 access_type; /* mask */
+ enum hv_intercept_type intercept_type;
+ union hv_intercept_parameters intercept_parameter;
+};
+
#endif
diff --git a/include/uapi/linux/mshv.h b/include/uapi/linux/mshv.h
index 5be9e2d23893..e784b2d1a3fd 100644
--- a/include/uapi/linux/mshv.h
+++ b/include/uapi/linux/mshv.h
@@ -41,6 +41,12 @@ struct mshv_vp_registers {
union hv_register_value *values;
};

+struct mshv_install_intercept {
+ __u32 access_type_mask;
+ enum hv_intercept_type intercept_type;
+ union hv_intercept_parameters intercept_parameter;
+};
+
#define MSHV_IOCTL 0xB8

/* mshv device */
@@ -51,6 +57,7 @@ struct mshv_vp_registers {
#define MSHV_MAP_GUEST_MEMORY _IOW(MSHV_IOCTL, 0x02, struct mshv_user_mem_region)
#define MSHV_UNMAP_GUEST_MEMORY _IOW(MSHV_IOCTL, 0x03, struct mshv_user_mem_region)
#define MSHV_CREATE_VP _IOW(MSHV_IOCTL, 0x04, struct mshv_create_vp)
+#define MSHV_INSTALL_INTERCEPT _IOW(MSHV_IOCTL, 0x08, struct mshv_install_intercept)

/* vp device */
#define MSHV_GET_VP_REGISTERS _IOWR(MSHV_IOCTL, 0x05, struct mshv_vp_registers)
diff --git a/virt/mshv/mshv_main.c b/virt/mshv/mshv_main.c
index 7ddb66d260ce..8392d5a45e04 100644
--- a/virt/mshv/mshv_main.c
+++ b/virt/mshv/mshv_main.c
@@ -1148,7 +1148,50 @@ mshv_partition_ioctl_unmap_memory(struct mshv_partition *partition,
}

static long
-mshv_partition_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
+mshv_partition_ioctl_install_intercept(struct mshv_partition *partition,
+ void __user *user_args)
+{
+ struct mshv_install_intercept args;
+ struct hv_install_intercept *input;
+ unsigned long flags;
+ int status;
+ int ret;
+
+ if (copy_from_user(&args, user_args, sizeof(args)))
+ return -EFAULT;
+
+ do {
+ local_irq_save(flags);
+ input = (struct hv_install_intercept *)(*this_cpu_ptr(
+ hyperv_pcpu_input_arg));
+ input->partition_id = partition->id;
+ input->access_type = args.access_type_mask;
+ input->intercept_type = args.intercept_type;
+ input->intercept_parameter = args.intercept_parameter;
+ status = hv_do_hypercall(
+ HVCALL_INSTALL_INTERCEPT, input, NULL) &
+ HV_HYPERCALL_RESULT_MASK;
+
+ local_irq_restore(flags);
+ if (status != HV_STATUS_INSUFFICIENT_MEMORY) {
+ if (status != HV_STATUS_SUCCESS) {
+ pr_err("%s: %s\n", __func__,
+ hv_status_to_string(status));
+ }
+ ret = -hv_status_to_errno(status);
+ break;
+ }
+
+ ret = hv_call_deposit_pages(NUMA_NO_NODE, partition->id, 1);
+
+ } while (!ret);
+
+ return ret;
+}
+
+static long
+mshv_partition_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
{
struct mshv_partition *partition = filp->private_data;
long ret;
@@ -1169,6 +1212,10 @@ mshv_partition_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
ret = mshv_partition_ioctl_create_vp(partition,
(void __user *)arg);
break;
+ case MSHV_INSTALL_INTERCEPT:
+ ret = mshv_partition_ioctl_install_intercept(partition,
+ (void __user *)arg);
+ break;
default:
ret = -ENOTTY;
}
--
2.25.1