On Mon, 25 Nov 2019 10:30:20 +0000
Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
Hi,
> The pci-shmem emulated device ("ivshmem") was created by QEMU for
> cross-VM data sharing. The only Linux driver that uses this device is
> the Android Virtual System on a Chip staging driver, which also mentions
> a character device driver implemented on top of shmem, which was removed
> from Linux.
>
> On the kvmtool side, the only commits touching the pci-shmem device
> since it was introduced in 2012 were made when refactoring various
> kvmtool subsystems. Let's remove the maintenance burden on the kvmtool
> maintainers and remove this unused device.
Yeah, sometimes you just have to let it go ;-)
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Cheers,
Andre
> ---
> Makefile | 1 -
> builtin-run.c | 5 -
> hw/pci-shmem.c | 400 ----------------------------------------
> include/kvm/pci-shmem.h | 32 ----
> 4 files changed, 438 deletions(-)
> delete mode 100644 hw/pci-shmem.c
> delete mode 100644 include/kvm/pci-shmem.h
>
> diff --git a/Makefile b/Makefile
> index 6d6880dd4f8a..99c6a9e24d72 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -99,7 +99,6 @@ OBJS += util/read-write.o
> OBJS += util/util.o
> OBJS += virtio/9p.o
> OBJS += virtio/9p-pdu.o
> -OBJS += hw/pci-shmem.o
> OBJS += kvm-ipc.o
> OBJS += builtin-sandbox.o
> OBJS += virtio/mmio.o
> diff --git a/builtin-run.c b/builtin-run.c
> index f8dc6c7229b0..9cb8c75300eb 100644
> --- a/builtin-run.c
> +++ b/builtin-run.c
> @@ -31,7 +31,6 @@
> #include "kvm/sdl.h"
> #include "kvm/vnc.h"
> #include "kvm/guest_compat.h"
> -#include "kvm/pci-shmem.h"
> #include "kvm/kvm-ipc.h"
> #include "kvm/builtin-debug.h"
>
> @@ -99,10 +98,6 @@ void kvm_run_set_wrapper_sandbox(void)
> OPT_INTEGER('c', "cpus", &(cfg)->nrcpus, "Number of CPUs"), \
> OPT_U64('m', "mem", &(cfg)->ram_size, "Virtual machine memory" \
> " size in MiB."), \
> - OPT_CALLBACK('\0', "shmem", NULL, \
> - "[pci:]<addr>:<size>[:handle=<handle>][:create]", \
> - "Share host shmem with guest via pci device", \
> - shmem_parser, NULL), \
> OPT_CALLBACK('d', "disk", kvm, "image or rootfs_dir", "Disk " \
> " image or rootfs directory", img_name_parser, \
> kvm), \
> diff --git a/hw/pci-shmem.c b/hw/pci-shmem.c
> deleted file mode 100644
> index f92bc75544d7..000000000000
> --- a/hw/pci-shmem.c
> +++ /dev/null
> @@ -1,400 +0,0 @@
> -#include "kvm/devices.h"
> -#include "kvm/pci-shmem.h"
> -#include "kvm/virtio-pci-dev.h"
> -#include "kvm/irq.h"
> -#include "kvm/kvm.h"
> -#include "kvm/pci.h"
> -#include "kvm/util.h"
> -#include "kvm/ioport.h"
> -#include "kvm/ioeventfd.h"
> -
> -#include <linux/kvm.h>
> -#include <linux/byteorder.h>
> -#include <sys/ioctl.h>
> -#include <fcntl.h>
> -#include <sys/mman.h>
> -
> -#define MB_SHIFT (20)
> -#define KB_SHIFT (10)
> -#define GB_SHIFT (30)
> -
> -static struct pci_device_header pci_shmem_pci_device = {
> - .vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
> - .device_id = cpu_to_le16(0x1110),
> - .header_type = PCI_HEADER_TYPE_NORMAL,
> - .class[2] = 0xFF, /* misc pci device */
> - .status = cpu_to_le16(PCI_STATUS_CAP_LIST),
> - .capabilities = (void *)&pci_shmem_pci_device.msix - (void *)&pci_shmem_pci_device,
> - .msix.cap = PCI_CAP_ID_MSIX,
> - .msix.ctrl = cpu_to_le16(1),
> - .msix.table_offset = cpu_to_le32(1), /* Use BAR 1 */
> - .msix.pba_offset = cpu_to_le32(0x1001), /* Use BAR 1 */
> -};
> -
> -static struct device_header pci_shmem_device = {
> - .bus_type = DEVICE_BUS_PCI,
> - .data = &pci_shmem_pci_device,
> -};
> -
> -/* registers for the Inter-VM shared memory device */
> -enum ivshmem_registers {
> - INTRMASK = 0,
> - INTRSTATUS = 4,
> - IVPOSITION = 8,
> - DOORBELL = 12,
> -};
> -
> -static struct shmem_info *shmem_region;
> -static u16 ivshmem_registers;
> -static int local_fd;
> -static u32 local_id;
> -static u64 msix_block;
> -static u64 msix_pba;
> -static struct msix_table msix_table[2];
> -
> -int pci_shmem__register_mem(struct shmem_info *si)
> -{
> - if (!shmem_region) {
> - shmem_region = si;
> - } else {
> - pr_warning("only single shmem currently avail. ignoring.\n");
> - free(si);
> - }
> - return 0;
> -}
> -
> -static bool shmem_pci__io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> - u16 offset = port - ivshmem_registers;
> -
> - switch (offset) {
> - case INTRMASK:
> - break;
> - case INTRSTATUS:
> - break;
> - case IVPOSITION:
> - ioport__write32(data, local_id);
> - break;
> - case DOORBELL:
> - break;
> - };
> -
> - return true;
> -}
> -
> -static bool shmem_pci__io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> -{
> - u16 offset = port - ivshmem_registers;
> -
> - switch (offset) {
> - case INTRMASK:
> - break;
> - case INTRSTATUS:
> - break;
> - case IVPOSITION:
> - break;
> - case DOORBELL:
> - break;
> - };
> -
> - return true;
> -}
> -
> -static struct ioport_operations shmem_pci__io_ops = {
> - .io_in = shmem_pci__io_in,
> - .io_out = shmem_pci__io_out,
> -};
> -
> -static void callback_mmio_msix(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len, u8 is_write, void *ptr)
> -{
> - void *mem;
> -
> - if (addr - msix_block < 0x1000)
> - mem = &msix_table;
> - else
> - mem = &msix_pba;
> -
> - if (is_write)
> - memcpy(mem + addr - msix_block, data, len);
> - else
> - memcpy(data, mem + addr - msix_block, len);
> -}
> -
> -/*
> - * Return an irqfd which can be used by other guests to signal this guest
> - * whenever they need to poke it
> - */
> -int pci_shmem__get_local_irqfd(struct kvm *kvm)
> -{
> - int fd, gsi, r;
> -
> - if (local_fd == 0) {
> - fd = eventfd(0, 0);
> - if (fd < 0)
> - return fd;
> -
> - if (pci_shmem_pci_device.msix.ctrl & cpu_to_le16(PCI_MSIX_FLAGS_ENABLE)) {
> - gsi = irq__add_msix_route(kvm, &msix_table[0].msg,
> - pci_shmem_device.dev_num << 3);
> - if (gsi < 0)
> - return gsi;
> - } else {
> - gsi = pci_shmem_pci_device.irq_line;
> - }
> -
> - r = irq__add_irqfd(kvm, gsi, fd, -1);
> - if (r < 0)
> - return r;
> -
> - local_fd = fd;
> - }
> -
> - return local_fd;
> -}
> -
> -/*
> - * Connect a new client to ivshmem by adding the appropriate datamatch
> - * to the DOORBELL
> - */
> -int pci_shmem__add_client(struct kvm *kvm, u32 id, int fd)
> -{
> - struct kvm_ioeventfd ioevent;
> -
> - ioevent = (struct kvm_ioeventfd) {
> - .addr = ivshmem_registers + DOORBELL,
> - .len = sizeof(u32),
> - .datamatch = id,
> - .fd = fd,
> - .flags = KVM_IOEVENTFD_FLAG_PIO | KVM_IOEVENTFD_FLAG_DATAMATCH,
> - };
> -
> - return ioctl(kvm->vm_fd, KVM_IOEVENTFD, &ioevent);
> -}
> -
> -/*
> - * Remove a client connected to ivshmem by removing the appropriate datamatch
> - * from the DOORBELL
> - */
> -int pci_shmem__remove_client(struct kvm *kvm, u32 id)
> -{
> - struct kvm_ioeventfd ioevent;
> -
> - ioevent = (struct kvm_ioeventfd) {
> - .addr = ivshmem_registers + DOORBELL,
> - .len = sizeof(u32),
> - .datamatch = id,
> - .flags = KVM_IOEVENTFD_FLAG_PIO
> - | KVM_IOEVENTFD_FLAG_DATAMATCH
> - | KVM_IOEVENTFD_FLAG_DEASSIGN,
> - };
> -
> - return ioctl(kvm->vm_fd, KVM_IOEVENTFD, &ioevent);
> -}
> -
> -static void *setup_shmem(const char *key, size_t len, int creating)
> -{
> - int fd;
> - int rtn;
> - void *mem;
> - int flag = O_RDWR;
> -
> - if (creating)
> - flag |= O_CREAT;
> -
> - fd = shm_open(key, flag, S_IRUSR | S_IWUSR);
> - if (fd < 0) {
> - pr_warning("Failed to open shared memory file %s\n", key);
> - return NULL;
> - }
> -
> - if (creating) {
> - rtn = ftruncate(fd, (off_t) len);
> - if (rtn < 0)
> - pr_warning("Can't ftruncate(fd,%zu)\n", len);
> - }
> - mem = mmap(NULL, len,
> - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
> - if (mem == MAP_FAILED) {
> - pr_warning("Failed to mmap shared memory file");
> - mem = NULL;
> - }
> - close(fd);
> -
> - return mem;
> -}
> -
> -int shmem_parser(const struct option *opt, const char *arg, int unset)
> -{
> - const u64 default_size = SHMEM_DEFAULT_SIZE;
> - const u64 default_phys_addr = SHMEM_DEFAULT_ADDR;
> - const char *default_handle = SHMEM_DEFAULT_HANDLE;
> - struct shmem_info *si = malloc(sizeof(struct shmem_info));
> - u64 phys_addr;
> - u64 size;
> - char *handle = NULL;
> - int create = 0;
> - const char *p = arg;
> - char *next;
> - int base = 10;
> - int verbose = 0;
> -
> - const int skip_pci = strlen("pci:");
> - if (verbose)
> - pr_info("shmem_parser(%p,%s,%d)", opt, arg, unset);
> - /* parse out optional addr family */
> - if (strcasestr(p, "pci:")) {
> - p += skip_pci;
> - } else if (strcasestr(p, "mem:")) {
> - die("I can't add to E820 map yet.\n");
> - }
> - /* parse out physical addr */
> - base = 10;
> - if (strcasestr(p, "0x"))
> - base = 16;
> - phys_addr = strtoll(p, &next, base);
> - if (next == p && phys_addr == 0) {
> - pr_info("shmem: no physical addr specified, using default.");
> - phys_addr = default_phys_addr;
> - }
> - if (*next != ':' && *next != '\0')
> - die("shmem: unexpected chars after phys addr.\n");
> - if (*next == '\0')
> - p = next;
> - else
> - p = next + 1;
> - /* parse out size */
> - base = 10;
> - if (strcasestr(p, "0x"))
> - base = 16;
> - size = strtoll(p, &next, base);
> - if (next == p && size == 0) {
> - pr_info("shmem: no size specified, using default.");
> - size = default_size;
> - }
> - /* look for [KMGkmg][Bb]* uses base 2. */
> - int skip_B = 0;
> - if (strspn(next, "KMGkmg")) { /* might have a prefix */
> - if (*(next + 1) == 'B' || *(next + 1) == 'b')
> - skip_B = 1;
> - switch (*next) {
> - case 'K':
> - case 'k':
> - size = size << KB_SHIFT;
> - break;
> - case 'M':
> - case 'm':
> - size = size << MB_SHIFT;
> - break;
> - case 'G':
> - case 'g':
> - size = size << GB_SHIFT;
> - break;
> - default:
> - die("shmem: bug in detecting size prefix.");
> - break;
> - }
> - next += 1 + skip_B;
> - }
> - if (*next != ':' && *next != '\0') {
> - die("shmem: unexpected chars after phys size. <%c><%c>\n",
> - *next, *p);
> - }
> - if (*next == '\0')
> - p = next;
> - else
> - p = next + 1;
> - /* parse out optional shmem handle */
> - const int skip_handle = strlen("handle=");
> - next = strcasestr(p, "handle=");
> - if (*p && next) {
> - if (p != next)
> - die("unexpected chars before handle\n");
> - p += skip_handle;
> - next = strchrnul(p, ':');
> - if (next - p) {
> - handle = malloc(next - p + 1);
> - strncpy(handle, p, next - p);
> - handle[next - p] = '\0'; /* just in case. */
> - }
> - if (*next == '\0')
> - p = next;
> - else
> - p = next + 1;
> - }
> - /* parse optional create flag to see if we should create shm seg. */
> - if (*p && strcasestr(p, "create")) {
> - create = 1;
> - p += strlen("create");
> - }
> - if (*p != '\0')
> - die("shmem: unexpected trailing chars\n");
> - if (handle == NULL) {
> - handle = malloc(strlen(default_handle) + 1);
> - strcpy(handle, default_handle);
> - }
> - if (verbose) {
> - pr_info("shmem: phys_addr = %llx",
> - (unsigned long long)phys_addr);
> - pr_info("shmem: size = %llx", (unsigned long long)size);
> - pr_info("shmem: handle = %s", handle);
> - pr_info("shmem: create = %d", create);
> - }
> -
> - si->phys_addr = phys_addr;
> - si->size = size;
> - si->handle = handle;
> - si->create = create;
> - pci_shmem__register_mem(si); /* ownership of si, etc. passed on. */
> - return 0;
> -}
> -
> -int pci_shmem__init(struct kvm *kvm)
> -{
> - char *mem;
> - int r;
> -
> - if (shmem_region == NULL)
> - return 0;
> -
> - /* Register MMIO space for MSI-X */
> - r = ioport__register(kvm, IOPORT_EMPTY, &shmem_pci__io_ops, IOPORT_SIZE, NULL);
> - if (r < 0)
> - return r;
> - ivshmem_registers = (u16)r;
> -
> - msix_block = pci_get_io_space_block(0x1010);
> - kvm__register_mmio(kvm, msix_block, 0x1010, false, callback_mmio_msix, NULL);
> -
> - /*
> - * This registers 3 BARs:
> - *
> - * 0 - ivshmem registers
> - * 1 - MSI-X MMIO space
> - * 2 - Shared memory block
> - */
> - pci_shmem_pci_device.bar[0] = cpu_to_le32(ivshmem_registers | PCI_BASE_ADDRESS_SPACE_IO);
> - pci_shmem_pci_device.bar_size[0] = shmem_region->size;
> - pci_shmem_pci_device.bar[1] = cpu_to_le32(msix_block | PCI_BASE_ADDRESS_SPACE_MEMORY);
> - pci_shmem_pci_device.bar_size[1] = 0x1010;
> - pci_shmem_pci_device.bar[2] = cpu_to_le32(shmem_region->phys_addr | PCI_BASE_ADDRESS_SPACE_MEMORY);
> - pci_shmem_pci_device.bar_size[2] = shmem_region->size;
> -
> - device__register(&pci_shmem_device);
> -
> - /* Open shared memory and plug it into the guest */
> - mem = setup_shmem(shmem_region->handle, shmem_region->size,
> - shmem_region->create);
> - if (mem == NULL)
> - return -EINVAL;
> -
> - kvm__register_dev_mem(kvm, shmem_region->phys_addr, shmem_region->size,
> - mem);
> - return 0;
> -}
> -dev_init(pci_shmem__init);
> -
> -int pci_shmem__exit(struct kvm *kvm)
> -{
> - return 0;
> -}
> -dev_exit(pci_shmem__exit);
> diff --git a/include/kvm/pci-shmem.h b/include/kvm/pci-shmem.h
> deleted file mode 100644
> index 6cff2b85bfd3..000000000000
> --- a/include/kvm/pci-shmem.h
> +++ /dev/null
> @@ -1,32 +0,0 @@
> -#ifndef KVM__PCI_SHMEM_H
> -#define KVM__PCI_SHMEM_H
> -
> -#include <linux/types.h>
> -#include <linux/list.h>
> -
> -#include "kvm/parse-options.h"
> -
> -#define SHMEM_DEFAULT_SIZE (16 << MB_SHIFT)
> -#define SHMEM_DEFAULT_ADDR (0xc8000000)
> -#define SHMEM_DEFAULT_HANDLE "/kvm_shmem"
> -
> -struct kvm;
> -struct shmem_info;
> -
> -struct shmem_info {
> - u64 phys_addr;
> - u64 size;
> - char *handle;
> - int create;
> -};
> -
> -int pci_shmem__init(struct kvm *kvm);
> -int pci_shmem__exit(struct kvm *kvm);
> -int pci_shmem__register_mem(struct shmem_info *si);
> -int shmem_parser(const struct option *opt, const char *arg, int unset);
> -
> -int pci_shmem__get_local_irqfd(struct kvm *kvm);
> -int pci_shmem__add_client(struct kvm *kvm, u32 id, int fd);
> -int pci_shmem__remove_client(struct kvm *kvm, u32 id);
> -
> -#endif
