From 248223259e22118b679aecfa27374b3f1c2e6ea6 Mon Sep 17 00:00:00 2001 From: Steffen Vogel Date: Wed, 21 Dec 2022 11:50:03 +0100 Subject: [PATCH] use C++ STL for handling file IO Signed-off-by: Steffen Vogel --- common/include/villas/kernel/pci.hpp | 15 ++- common/lib/kernel/pci.cpp | 141 +++++++++------------------ common/lib/kernel/vfio_container.cpp | 10 +- 3 files changed, 63 insertions(+), 103 deletions(-) diff --git a/common/include/villas/kernel/pci.hpp b/common/include/villas/kernel/pci.hpp index cc34aab4b..caa914a54 100644 --- a/common/include/villas/kernel/pci.hpp +++ b/common/include/villas/kernel/pci.hpp @@ -8,10 +8,12 @@ #pragma once +#include +#include + #include #include -#include #include namespace villas { @@ -97,23 +99,26 @@ public: std::list getRegions() const; // Write 32-bit BAR value from to the PCI configuration space - bool writeBar(uint32_t new_bar); + void writeBar(uint32_t addr, unsigned bar = 0); // If BAR values in config space and in the kernel do not match, rewrite // the BAR value of the kernel to PCIe config space. - bool rewriteBar(); + void rewriteBar(unsigned bar = 0); // Read 32-bit BAR value from the PCI configuration space. - bool readBar(uint32_t &bar) const; + uint32_t readBar(unsigned bar = 0) const; // Read 32-bit BAR value from the devices resource file. This is what the kernel // thinks the BAR should be. - bool readHostBar(uint32_t &bar) const; + uint32_t readHostBar(unsigned bar = 0) const; Id id; Slot slot; private: villas::Logger log; + +protected: + std::fstream openSysFs(const std::string subPath, std::ios_base::openmode mode = std::ios_base::in | std::ios_base::out) const; }; class DeviceList : public std::list> { diff --git a/common/lib/kernel/pci.cpp b/common/lib/kernel/pci.cpp index 8f3203476..32666f527 100644 --- a/common/lib/kernel/pci.cpp +++ b/common/lib/kernel/pci.cpp @@ -362,124 +362,64 @@ bool Device::attachDriver(const std::string &driver) const return true; } - -bool Device::readHostBar(uint32_t &bar) const +uint32_t Device::readHostBar(unsigned bar) const { - unsigned long long start, end, size, flags; + auto file = openSysFs("resource", std::ios_base::in); - char *path = NULL; - if (asprintf(&path, "%s/bus/pci/devices/%04x:%02x:%02x.%x/resource", SYSFS_PATH, - slot.domain, slot.bus, slot.device, slot.function) == -1) { - log->error("could not allocate memory for path"); - return false; - } + std::string line; - FILE *file = fopen(path, "r"); - if (!file) { - log->error("error opening resource file"); - return false; - } + unsigned i; + for (i = 0; i <= bar && !file.eof(); i++) + std::getline(file, line); - if (fscanf(file, "%llx %llx %llx", &start, &end, &flags) != 3) { - log->error("error reading resource file"); - fclose(file); - return false; - } + if (i != bar && file.eof()) + throw RuntimeError("Failed to read resource file"); + + unsigned long long start, end, flags; + std::istringstream(line) >> std::hex >> start >> end >> flags; if (end > start) - size = end - start + 1; - else { - log->error("error reading bar size"); - fclose(file); - return false; - } + throw SystemError("Invalid BAR: start={}, end={}", start, end); - log->debug("Start: {:#x}, end: {:#x}, size: {:#x}, flags: {:#x}", start, end, size, flags); + log->debug("Host BAR: start={:#x}, end={:#x}, flags={:#x}", start, end, flags); - fclose(file); - bar = start; - - return true; + return start; } -bool Device::rewriteBar() +void Device::rewriteBar(unsigned bar) { - uint32_t hostbar, configbar; - if (!readHostBar(hostbar)) { - log->error("Error reading host bar"); - return false; - } + auto hostBar = readHostBar(bar); + auto configBar = readBar(bar); - if (!readBar(configbar)) { - log->error("Error reading config bar"); - return false; - } - log->debug("Host BAR: {:#x}, configbar: {:#x}", hostbar, configbar); + log->debug("Host BAR: {:#x}, configbar: {:#x}", hostBar, configBar); - if (hostbar == configbar) { + if (hostBar == configBar) { log->debug("BAR is already correct"); - return true; - } else { - log->debug("BAR is incorrect, rewriting"); - return writeBar(hostbar); + return; } + + log->debug("BAR is incorrect, rewriting"); + + writeBar(hostBar, bar); } -bool Device::readBar(uint32_t &bar) const +uint32_t Device::readBar(unsigned bar) const { - off_t pos = PCI_BASE_ADDRESS_0; - uint32_t read_buf; - char *path = NULL; - if (asprintf(&path, "%s/bus/pci/devices/%04x:%02x:%02x.%x/config", SYSFS_PATH, - slot.domain, slot.bus, slot.device, slot.function) == -1) { - log->error("could not allocate memory for path"); - return false; - } + uint32_t addr; + auto file = openSysFs("config", std::ios_base::in); - int fd = open(path, O_RDWR); - if (fd < 0) { - log->error("could not open config space"); - return false; - } + file.seekg(PCI_BASE_ADDRESS_0 + sizeof(uint32_t) * bar); + file.read(reinterpret_cast(&addr), sizeof(addr)); - if (pread(fd, &read_buf, sizeof(read_buf), pos) != sizeof(read_buf)) { - log->error("error reading from {:#x}", pos); - close(fd); - return false; - } - - bar = read_buf; - close(fd); - - return true; + return addr; } -bool Device::writeBar(uint32_t new_bar) +void Device::writeBar(uint32_t addr, unsigned bar) { - uint32_t write_buf = new_bar; - off_t pos = PCI_BASE_ADDRESS_0; - char *path = NULL; + auto file = openSysFs("config", std::ios_base::out); - if (asprintf(&path, "%s/bus/pci/devices/%04x:%02x:%02x.%x/config", SYSFS_PATH, - slot.domain, slot.bus, slot.device, slot.function) == -1) { - log->error("could not allocate memory for path"); - return false; - } - - int fd = open(path, O_RDWR); - if (fd < 0) { - log->error("could not open config space"); - return false; - } - - if (pwrite(fd, &write_buf, sizeof(write_buf), pos) != sizeof(write_buf)) { - log->error("error writing to {:#x}", pos); - close(fd); - return false; - } - - close(fd); - return true; + file.seekp(PCI_BASE_ADDRESS_0 + sizeof(uint32_t) * bar); + file.write(reinterpret_cast(&addr), sizeof(addr)); } int Device::getIommuGroup() const @@ -502,3 +442,16 @@ int Device::getIommuGroup() const return atoi(group); } + +std::fstream Device::openSysFs(const std::string subPath, std::ios_base::openmode mode) const +{ + std::fstream file; + + auto sysFsFilename = fmt::format("{}/bus/pci/devices/{:04x}:{:02x}:{:02x}.{:x}/{}", SYSFS_PATH, + slot.domain, slot.bus, slot.device, slot.function, subPath); + + file.exceptions(std::ifstream::failbit | std::ifstream::badbit); + file.open(sysFsFilename, mode); + + return file; +} diff --git a/common/lib/kernel/vfio_container.cpp b/common/lib/kernel/vfio_container.cpp index c63b3c8b7..03f1af557 100644 --- a/common/lib/kernel/vfio_container.cpp +++ b/common/lib/kernel/vfio_container.cpp @@ -207,10 +207,12 @@ std::shared_ptr Container::attachDevice(pci::Device &pdev) log->debug("Bind PCI card to kernel driver '{}'", kernelDriver); pdev.attachDriver(kernelDriver); } - if (!pdev.rewriteBar()) { - log->error("BAR of device is in inconsistent state. Rewriting the BAR " - "failed. Please remove, rescan and reset the device and try again."); - throw RuntimeError("Failed to rewrite BAR of device"); + + try { + pdev.rewriteBar(); + } catch (std::exception &e) { + throw RuntimeError("BAR of device is in inconsistent state. Rewriting the BAR " + "failed. Please remove, rescan and reset the device and try again."); } // Get IOMMU group of device