support scsi uring_cmd

.github/workflows/ci-latest-kernel.yml

@@ -82,7 +82,7 @@ jobs:
         timeout-minutes: 15
         run: |
           bash ./scripts/vm-run.sh \
-            -c "CONDY_TEST_NVME_DEVICE_PATH=/dev/nvme0n1 CONDY_TEST_NVME_NG_DEVICE_PATH=/dev/ng0n1 ./tests" \
+            -c "CONDY_TEST_NVME_DEVICE_PATH=/dev/nvme0n1 CONDY_TEST_NVME_NG_DEVICE_PATH=/dev/ng0n1 CONDY_TEST_BSG_DEVICE_PATH=/dev/bsg/0:0:0:0 ./tests" \
             ./.cache/bzImage ./build/tests/tests \
             2>&1 | tee vm-run.log
           if grep -q "SUCCESS!" vm-run.log; then

include/condy/cqe_handler.hpp

@@ -65,6 +65,47 @@ struct NVMePassthruCQEHandler {
     }
 };
 
+/**
+ * @brief Result for SCSI BSG passthrough commands.
+ * @details Contains the raw res2 from the CQE. Use the member functions
+ * to extract individual fields.
+ */
+struct SCSIBsgResult {
+    /** @brief Raw res2 from the CQE. */
+    uint64_t res2;
+
+    /** @brief Extract SCSI device status byte. */
+    uint8_t device_status() noexcept { return res2 & 0xff; }
+
+    /** @brief Extract driver status. */
+    uint8_t driver_status() noexcept { return (res2 >> 8) & 0xff; }
+
+    /** @brief Extract host status. */
+    uint8_t host_status() noexcept { return (res2 >> 16) & 0xff; }
+
+    /** @brief Extract sense data length. */
+    uint8_t sense_len() noexcept { return (res2 >> 24) & 0xff; }
+
+    /** @brief Extract residual transfer length. */
+    uint32_t resid_len() noexcept { return res2 >> 32; }
+};
+
+/**
+ * @brief A CQE handler for SCSI BSG passthrough commands that extracts the
+ * SCSI status and result from the CQE.
+ * @return std::pair<int32_t, SCSIBsgResult> A pair containing the result of
+ * the operation (the value of `cqe->res`) and the raw SCSI status.
+ */
+struct SCSIBsgPassthruCQEHandler {
+    std::pair<int32_t, SCSIBsgResult> operator()(io_uring_cqe *cqe) noexcept {
+        assert(
+            detail::Context::current().runtime()->ring_internal().check_cqe32(
+                cqe) &&
+            "Expected big CQE for SCSI BSG passthrough");
+        return {cqe->res, SCSIBsgResult{cqe->big_cqe[0]}};
+    }
+};
+
 #if CONDY_URING_VERSION_GE(2, 12) // >= 2.12
 /**
  * @brief Result for TX timestamp operations, containing timestamp information

module/condy.cppm

@@ -63,6 +63,8 @@ using condy::ZeroCopyRxDMABufArea;
 
 // cqe_handler.hpp
 using condy::NVMePassthruCQEHandler;
+using condy::SCSIBsgPassthruCQEHandler;
+using condy::SCSIBsgResult;
 using condy::SelectBufferCQEHandler;
 using condy::SimpleCQEHandler;
 #if CONDY_URING_VERSION_GE(2, 12) // >= 2.12

scripts/light-kernel.sh

@@ -60,6 +60,13 @@ make kvm_guest.config
 ./scripts/config --enable CONFIG_NVME_CORE
 ./scripts/config --enable CONFIG_BLK_DEV_NVME
 ./scripts/config --enable CONFIG_NVME_MULTIPATH
+# Configure SCSI and BSG support
+./scripts/config --enable CONFIG_SCSI
+./scripts/config --enable CONFIG_BLK_DEV_SD
+./scripts/config --enable CONFIG_SCSI_LOWLEVEL
+./scripts/config --enable CONFIG_SCSI_VIRTIO
+./scripts/config --enable CONFIG_VIRTIO_PCI
+./scripts/config --enable CONFIG_BLK_DEV_BSG
 # Use olddefconfig to set new options to default values
 make olddefconfig
 

scripts/vm-run.sh

@@ -88,6 +88,13 @@ trap "rm -f '$SSD_IMG'; rm -rf $TEMP_DIR" EXIT
 SSD_DRIVE="-drive file=$SSD_IMG,if=none,id=ssd0,format=raw,cache=none,aio=io_uring"
 SSD_DEVICE="-device nvme,drive=ssd0,serial=ssd0"
 
+# Simulate SCSI disk for BSG testing
+SCSI_IMG="/dev/shm/vm-scsi.img.$$"
+truncate -s 16M "$SCSI_IMG"
+trap "rm -f '$SSD_IMG' '$SCSI_IMG'; rm -rf $TEMP_DIR" EXIT
+SCSI_DRIVE="-drive file=$SCSI_IMG,if=none,id=scsi0,format=raw"
+SCSI_DEVICE="-device virtio-scsi-pci,id=scsi0 -device scsi-hd,drive=scsi0,bus=scsi0.0"
+
 KVM_FLAG=""
 if [ "$KVM_ENABLED" = true ]; then
     KVM_FLAG="-enable-kvm"
@@ -115,4 +122,6 @@ qemu-system-x86_64 \
     -append "$KERNEL_ARGS" \
     -nographic \
     $SSD_DRIVE \
-    $SSD_DEVICE
+    $SSD_DEVICE \
+    $SCSI_DRIVE \
+    $SCSI_DEVICE

tests/helpers.hpp

@@ -7,6 +7,7 @@
 #include <cstring>
 #include <doctest.h>
 #include <fcntl.h>
+#include <linux/bsg.h>
 #include <linux/futex.h>
 #include <linux/nvme_ioctl.h>
 #include <netinet/in.h>
@@ -231,4 +232,29 @@ inline auto my_cmd_nvme_write(Fd fd, const void *buf, size_t buf_size,
 #endif
 }
 
+template <bool SQE128 = false, condy::FdLike Fd>
+inline auto my_cmd_scsi_test_unit_ready(Fd fd) {
+    static const uint8_t cdb[6] = {0}; // TEST UNIT READY (opcode 0x00)
+    auto cmd_func = [=](io_uring_sqe *sqe) {
+        struct bsg_uring_cmd *cmd = (struct bsg_uring_cmd *)sqe->cmd;
+        memset(cmd, 0, sizeof(struct bsg_uring_cmd));
+        cmd->protocol = BSG_PROTOCOL_SCSI;
+        cmd->subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
+        cmd->request = (__u64)(uintptr_t)cdb;
+        cmd->request_len = 6;
+    };
+#if CONDY_URING_VERSION_GE(2, 13) // >= 2.13
+    if constexpr (SQE128) {
+        return condy::async_uring_cmd128<condy::SCSIBsgPassthruCQEHandler>(
+            0, fd, cmd_func);
+    } else {
+        return condy::async_uring_cmd<condy::SCSIBsgPassthruCQEHandler>(
+            0, fd, cmd_func);
+    }
+#else
+    return condy::async_uring_cmd<condy::SCSIBsgPassthruCQEHandler>(
+        0, fd, cmd_func);
+#endif
+}
+
 } // namespace

tests/test_async_operations.4.cpp

@@ -13,6 +13,7 @@
 #include <cstring>
 #include <doctest.h>
 #include <fcntl.h>
+#include <linux/bsg.h>
 #include <linux/errqueue.h>
 #include <linux/futex.h>
 #include <linux/net_tstamp.h>
@@ -390,6 +391,60 @@ TEST_CASE(
     close(fd);
 }
 
+TEST_CASE("test async_operations - test uring_cmd - scsi bsg - basic") {
+    const char *bsg_device_path = std::getenv("CONDY_TEST_BSG_DEVICE_PATH");
+    if (bsg_device_path == nullptr) {
+        MESSAGE("CONDY_TEST_BSG_DEVICE_PATH not set, skipping");
+        return;
+    }
+
+    int fd = open(bsg_device_path, O_RDWR);
+    REQUIRE(fd >= 0);
+
+    condy::Runtime runtime(
+        condy::RuntimeOptions().enable_sqe128().enable_cqe32());
+
+    auto func = [&]() -> condy::Coro<void> {
+        auto [status, result] = co_await my_cmd_scsi_test_unit_ready(fd);
+        REQUIRE(status == 0);
+        REQUIRE(result.device_status() == 0);
+        REQUIRE(result.host_status() == 0);
+    };
+    condy::sync_wait(runtime, func());
+
+    close(fd);
+}
+
+TEST_CASE("test async_operations - test uring_cmd - scsi bsg - fixed fd") {
+    const char *bsg_device_path = std::getenv("CONDY_TEST_BSG_DEVICE_PATH");
+    if (bsg_device_path == nullptr) {
+        MESSAGE("CONDY_TEST_BSG_DEVICE_PATH not set, skipping");
+        return;
+    }
+
+    int fd = open(bsg_device_path, O_RDWR);
+    REQUIRE(fd >= 0);
+
+    condy::Runtime runtime(
+        condy::RuntimeOptions().enable_sqe128().enable_cqe32());
+
+    auto func = [&]() -> condy::Coro<void> {
+        auto &fd_table = condy::current_runtime().fd_table();
+        fd_table.init(1);
+        int r = co_await condy::async_files_update(&fd, 1, 0);
+        REQUIRE(r == 1);
+
+        auto [status, result] =
+            co_await my_cmd_scsi_test_unit_ready(condy::fixed(0));
+        REQUIRE(status == 0);
+        REQUIRE(result.device_status() == 0);
+        REQUIRE(result.host_status() == 0);
+    };
+    condy::sync_wait(runtime, func());
+
+    close(fd);
+}
+
 #if CONDY_URING_VERSION_GE(2, 12) // >= 2.12
 TEST_CASE("test async_operations - test uring_cmd_multishot - tx timestamp") {
     int r;
@@ -577,6 +632,60 @@ TEST_CASE(
 
     close(fd);
 }
+
+TEST_CASE("test async_operations - test uring_cmd128 - scsi bsg - basic") {
+    const char *bsg_device_path = std::getenv("CONDY_TEST_BSG_DEVICE_PATH");
+    if (bsg_device_path == nullptr) {
+        MESSAGE("CONDY_TEST_BSG_DEVICE_PATH not set, skipping");
+        return;
+    }
+
+    int fd = open(bsg_device_path, O_RDWR);
+    REQUIRE(fd >= 0);
+
+    condy::Runtime runtime(
+        condy::RuntimeOptions().enable_sqe_mixed().enable_cqe_mixed());
+
+    auto func = [&]() -> condy::Coro<void> {
+        auto [status, result] = co_await my_cmd_scsi_test_unit_ready<true>(fd);
+        REQUIRE(status == 0);
+        REQUIRE(result.device_status() == 0);
+        REQUIRE(result.host_status() == 0);
+    };
+    condy::sync_wait(runtime, func());
+
+    close(fd);
+}
+
+TEST_CASE("test async_operations - test uring_cmd128 - scsi bsg - fixed fd") {
+    const char *bsg_device_path = std::getenv("CONDY_TEST_BSG_DEVICE_PATH");
+    if (bsg_device_path == nullptr) {
+        MESSAGE("CONDY_TEST_BSG_DEVICE_PATH not set, skipping");
+        return;
+    }
+
+    int fd = open(bsg_device_path, O_RDWR);
+    REQUIRE(fd >= 0);
+
+    condy::Runtime runtime(
+        condy::RuntimeOptions().enable_sqe_mixed().enable_cqe_mixed());
+
+    auto func = [&]() -> condy::Coro<void> {
+        auto &fd_table = condy::current_runtime().fd_table();
+        fd_table.init(1);
+        int r = co_await condy::async_files_update(&fd, 1, 0);
+        REQUIRE(r == 1);
+
+        auto [status, result] =
+            co_await my_cmd_scsi_test_unit_ready<true>(condy::fixed(0));
+        REQUIRE(status == 0);
+        REQUIRE(result.device_status() == 0);
+        REQUIRE(result.host_status() == 0);
+    };
+    condy::sync_wait(runtime, func());
+
+    close(fd);
+}
 #endif
 
 #if CONDY_URING_VERSION_GE(2, 5) // >= 2.5