Merge pull request #119 from softickllc/irqfd

shim: Initial support for KVM_IRQFD

shim/include/handle_vm_kvm_irqfd.h

@@ -29,6 +29,7 @@
 
 #include <kvm_irqfd.h>
 #include <mv_types.h>
+#include <shim_vm_t.h>
 
 #ifdef __cplusplus
 extern "C"
@@ -40,10 +41,12 @@ extern "C"
      *   @brief Handles the execution of kvm_irqfd.
      *
      * <!-- inputs/outputs -->
+     *   @param pmut_vm the argumento hold vm details of type shim_vm_t
      *   @param pmut_ioctl_args the arguments provided by userspace
      *   @return SHIM_SUCCESS on success, SHIM_FAILURE on failure.
      */
-    NODISCARD int64_t handle_vm_kvm_irqfd(struct kvm_irqfd *const pmut_ioctl_args) NOEXCEPT;
+    NODISCARD int64_t handle_vm_kvm_irqfd(
+        struct shim_vm_t *const pmut_vm, struct kvm_irqfd *const pmut_ioctl_args) NOEXCEPT;
 
 #ifdef __cplusplus
 }

shim/include/kvm_irqfd.h

@@ -29,23 +29,38 @@
 
 #include <stdint.h>
 
+#ifdef __clang__
+#pragma clang diagnostic ignored "-Wold-style-cast"
+#endif
+
 #ifdef __cplusplus
 extern "C"
 {
 #endif
 
 #pragma pack(push, 1)
 
+/** @brief defines the padding size */
+#define PAD_SIZE_IRQFD ((uint32_t)16)
+
     /**
      * @struct kvm_irqfd
      *
      * <!-- description -->
-     *   @brief see /include/uapi/linux/kvm.h in Linux for more details.
+     *   @brief Allows setting an eventfd to directly trigger a guest interrupt..
      */
     struct kvm_irqfd
     {
-        /** @brief replace me with contents from KVM API */
-        int32_t dummy;
+        /** @brief specifies the file descriptor to use as the eventfd */
+        uint32_t fd;
+        /** @brief specifies the irqchip pin toggled by this event*/
+        uint32_t gsi;
+        /** @brief The flag is used to remove irqfd */
+        uint32_t flags;
+        /** @brief Additional eventfd the user must pass when KVM_IRQFD_FLAG_RESAMPLE is set */
+        uint32_t resamplefd;
+        /** @brief TODO*/
+        uint8_t pad[PAD_SIZE_IRQFD];
     };
 
 #pragma pack(pop)

shim/include/kvm_irqfd.hpp

@@ -0,0 +1,60 @@
+/// @copyright
+/// Copyright (C) 2020 Assured Information Security, Inc.
+///
+/// @copyright
+/// Permission is hereby granted, free of charge, to any person obtaining a copy
+/// of this software and associated documentation files (the "Software"), to deal
+/// in the Software without restriction, including without limitation the rights
+/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+/// copies of the Software, and to permit persons to whom the Software is
+/// furnished to do so, subject to the following conditions:
+///
+/// @copyright
+/// The above copyright notice and this permission notice shall be included in
+/// all copies or substantial portions of the Software.
+///
+/// @copyright
+/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+/// SOFTWARE.
+
+#ifndef KVM_IRQFD_HPP
+#define KVM_IRQFD_HPP
+
+#include <bsl/array.hpp>
+#include <bsl/convert.hpp>
+#include <bsl/safe_integral.hpp>
+
+#pragma pack(push, 1)
+
+namespace shim
+{
+    /// @brief defines the size of the padding field
+    constexpr auto PAD_SIZE_IRQFD{16_umx};
+    /// @struct kvm_irqfd
+    ///
+    /// <!-- description -->
+    ///   @brief Allows setting an eventfd to directly trigger a guest interrupt.
+    ///
+    struct kvm_irqfd final
+    {
+        /** @brief specifies the file descriptor to use as the eventfd */
+        bsl::uint32 fd;
+        /** @brief specifies the irqchip pin toggled by this event*/
+        bsl::uint32 gsi;
+        /** @brief The flag is used to remove irqfd */
+        bsl::uint32 flags;
+        /** @brief Additional eventfd the user must pass when KVM_IRQFD_FLAG_RESAMPLE is set */
+        bsl::uint32 resamplefd;
+        /** @brief TODO*/
+        bsl::array<bsl::uint8, PAD_SIZE_IRQFD.get()> pad;
+    };
+}
+
+#pragma pack(pop)
+
+#endif

shim/integration/CMakeLists.txt

@@ -55,3 +55,4 @@ microv_add_shim_integration(kvm_get_irqchip HEADERS)
 microv_add_shim_integration(kvm_set_irqchip HEADERS)
 microv_add_shim_integration(kvm_get_lapic HEADERS)
 microv_add_shim_integration(kvm_set_lapic HEADERS)
+microv_add_shim_integration(kvm_irqfd HEADERS)

shim/integration/kvm_irqfd.cpp

@@ -0,0 +1,56 @@
+/// @copyright
+/// Copyright (C) 2020 Assured Information Security, Inc.
+///
+/// @copyright
+/// Permission is hereby granted, free of charge, to any person obtaining a copy
+/// of this software and associated documentation files (the "Software"), to deal
+/// in the Software without restriction, including without limitation the rights
+/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+/// copies of the Software, and to permit persons to whom the Software is
+/// furnished to do so, subject to the following conditions:
+///
+/// @copyright
+/// The above copyright notice and this permission notice shall be included in
+/// all copies or substantial portions of the Software.
+///
+/// @copyright
+/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+/// SOFTWARE.
+
+#include <integration_utils.hpp>
+#include <ioctl_t.hpp>
+#include <shim_platform_interface.hpp>
+
+#include <bsl/convert.hpp>
+#include <bsl/enable_color.hpp>
+#include <bsl/exit_code.hpp>
+#include <bsl/safe_integral.hpp>
+
+/// <!-- description -->
+///   @brief Provides the main entry point for this application.
+///
+/// <!-- inputs/outputs -->
+///   @return bsl::exit_success on success, bsl::exit_failure otherwise.
+///
+[[nodiscard]] auto
+main() noexcept -> bsl::exit_code
+{
+    bsl::enable_color();
+    integration::ioctl_t mut_system_ctl{shim::DEVICE_NAME};
+    auto const vmfd{mut_system_ctl.send(shim::KVM_CREATE_VM)};
+    integration::ioctl_t mut_vm{bsl::to_i32(vmfd)};
+    auto const vcpufd{mut_vm.send(shim::KVM_CREATE_VCPU)};
+    integration::ioctl_t mut_vcpu{bsl::to_i32(vcpufd)};
+    constexpr auto mut_ret{0_i64};
+    {
+        auto const irqfd{mut_vcpu.send(shim::KVM_IRQFD)};
+        integration::verify(irqfd.is_pos());
+        integration::verify(irqfd >= mut_ret.get());
+    }
+    return bsl::exit_success;
+}

shim/linux/include/platform_interface/shim_platform_interface.hpp

@@ -32,6 +32,7 @@
 #include <kvm_cpuid_entry2.hpp>
 #include <kvm_fpu.hpp>
 #include <kvm_irqchip.hpp>
+#include <kvm_irqfd.hpp>
 #include <kvm_mp_state.hpp>
 #include <kvm_msr_entry.hpp>
 #include <kvm_msr_list.hpp>
@@ -246,8 +247,9 @@ namespace shim
     // constexpr bsl::safe_umx KVM_GET_PIT2{static_cast<bsl::uintmx>(_IOR(SHIMIO.get(), 0x9f, struct kvm_pit_state2))};
     // /// @brief defines KVM's KVM_SET_PIT2 IOCTL
     // constexpr bsl::safe_umx KVM_SET_PIT2{static_cast<bsl::uintmx>(_IOW(SHIMIO.get(), 0xa0, struct kvm_pit_state2))};
-    // /// @brief defines KVM's KVM_IRQFD IOCTL
-    // constexpr bsl::safe_umx KVM_IRQFD{static_cast<bsl::uintmx>(_IOW(SHIMIO.get(), 0x76, struct kvm_irqfd))};
+    /// @brief defines KVM's KVM_IRQFD IOCTL
+    constexpr bsl::safe_umx KVM_IRQFD{
+        static_cast<bsl::uintmx>(_IOW(SHIMIO.get(), 0x76, struct kvm_irqfd))};
     // /// @brief defines KVM's KVM_CREATE_DEVICE IOCTL
     // constexpr bsl::safe_umx KVM_CREATE_DEVICE{static_cast<bsl::uintmx>(_IOWR(SHIMIO.get(), 0xe0, struct kvm_create_device))};
     // /// @brief defines KVM's KVM_GET_DEVICE_ATTR IOCTL

shim/linux/src/entry.c

@@ -55,6 +55,7 @@
 #include <handle_vm_kvm_create_vcpu.h>
 #include <handle_vm_kvm_destroy_vcpu.h>
 #include <handle_vm_kvm_get_irqchip.h>
+#include <handle_vm_kvm_irqfd.h>
 #include <handle_vm_kvm_set_irqchip.h>
 #include <handle_vm_kvm_set_user_memory_region.h>
 #include <linux/anon_inodes.h>
@@ -661,10 +662,23 @@ dispatch_vm_kvm_irq_line(struct kvm_irq_level *const ioctl_args)
 }
 
 static long
-dispatch_vm_kvm_irqfd(struct kvm_irqfd *const ioctl_args)
+dispatch_vm_kvm_irqfd(
+    struct shim_vm_t *const pmut_vm, struct kvm_irqfd *const pmut_ioctl_args)
 {
-    (void)ioctl_args;
-    return -EINVAL;
+    struct kvm_irqfd mut_args;
+    uint64_t const size = sizeof(mut_args);
+
+    if (platform_copy_from_user(&mut_args, pmut_ioctl_args, size)) {
+        bferror("platform_copy_from_user failed");
+        return -EINVAL;
+    }
+
+    if (handle_vm_kvm_irqfd(pmut_vm, &mut_args)) {
+        bferror("handle_vm_kvm_irqfd failed");
+        return -EINVAL;
+    }
+
+    return 0;
 }
 
 static long
@@ -903,7 +917,9 @@ dev_unlocked_ioctl_vm(
         }
 
         case KVM_IRQFD: {
-            return dispatch_vm_kvm_irqfd((struct kvm_irqfd *)ioctl_args);
+            return dispatch_vm_kvm_irqfd(
+                (struct shim_vm_t *)pmut_mut_vm,
+                (struct kvm_irqfd *)ioctl_args);
         }
 
         case KVM_REGISTER_COALESCED_MMIO: {

shim/src/handle_vm_kvm_irqfd.c

@@ -24,20 +24,34 @@
  * SOFTWARE.
  */
 
+#include <debug.h>
+#include <detect_hypervisor.h>
 #include <kvm_irqfd.h>
 #include <mv_types.h>
+#include <platform.h>
+#include <shim_vm_t.h>
 
 /**
  * <!-- description -->
  *   @brief Handles the execution of kvm_irqfd.
  *
  * <!-- inputs/outputs -->
+ *   @param pmut_vm the argumento hold vm details of type shim_vm_t
  *   @param pmut_ioctl_args the arguments provided by userspace
  *   @return SHIM_SUCCESS on success, SHIM_FAILURE on failure.
  */
 NODISCARD int64_t
-handle_vm_kvm_irqfd(struct kvm_irqfd *const pmut_ioctl_args) NOEXCEPT
+handle_vm_kvm_irqfd(
+    struct shim_vm_t *const pmut_vm, struct kvm_irqfd *const pmut_ioctl_args) NOEXCEPT
 {
-    (void)pmut_ioctl_args;
+    platform_expects(NULL != pmut_vm);
+    platform_expects(NULL != pmut_ioctl_args);
+
+    if (detect_hypervisor()) {
+        bferror("The shim is not running in a VM. Did you forget to start MicroV?");
+        return SHIM_FAILURE;
+    }
+    //TODO: Cally the hypercall here after its implementation
+
     return SHIM_SUCCESS;
 }

shim/tests/src/test_handle_vm_kvm_irqfd.cpp

@@ -23,9 +23,10 @@
 /// SOFTWARE.
 
 #include "../../include/handle_vm_kvm_irqfd.h"
+#include "shim_vm_t.h"
 
+#include <helpers.hpp>
 #include <kvm_irqfd.h>
-#include <mv_types.h>
 
 #include <bsl/ut.hpp>
 
@@ -43,12 +44,30 @@ namespace shim
     [[nodiscard]] constexpr auto
     tests() noexcept -> bsl::exit_code
     {
+        init_tests();
         bsl::ut_scenario{"description"} = []() noexcept {
             bsl::ut_given{} = [&]() noexcept {
                 kvm_irqfd mut_args{};
+                shim_vm_t mut_vm{};
                 bsl::ut_when{} = [&]() noexcept {
                     bsl::ut_then{} = [&]() noexcept {
-                        bsl::ut_check(SHIM_SUCCESS == handle_vm_kvm_irqfd(&mut_args));
+                        bsl::ut_check(SHIM_SUCCESS == handle_vm_kvm_irqfd(&mut_vm, &mut_args));
+                    };
+                };
+            };
+        };
+
+        bsl::ut_scenario{"hypervisor not detected"} = []() noexcept {
+            bsl::ut_given{} = [&]() noexcept {
+                kvm_irqfd mut_args{};
+                shim_vm_t mut_vm{};
+                bsl::ut_when{} = [&]() noexcept {
+                    g_mut_hypervisor_detected = false;
+                    bsl::ut_then{} = [&]() noexcept {
+                        bsl::ut_check(SHIM_FAILURE == handle_vm_kvm_irqfd(&mut_vm, &mut_args));
+                    };
+                    bsl::ut_cleanup{} = [&]() noexcept {
+                        g_mut_hypervisor_detected = true;
                     };
                 };
             };