Re: [Qemu-devel] [PATCH RFC V3 10/12] xen: Initialize event channels and io rings

[Blue Swirl]

On Fri, Sep 17, 2010 at 11:15 AM,  <address@hidden> wrote:
> From: Anthony PERARD <address@hidden>
>
> Open and bind event channels; map ioreq and buffered ioreq rings.

In general, because of CPUState accesses and cpu_in/out use, this
looks like CPU code, specifically x86. Could this belong to
target-i386/xen.c instead, much like target-i386/kvm.c vs ./kvm-all.c?
Do other CPU types use this stuff?

>
> Signed-off-by: Anthony PERARD <address@hidden>
> Signed-off-by: Stefano Stabellini <address@hidden>
> ---
>  hw/xen_common.h |    1 +
>  xen-all.c       |  381 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 382 insertions(+), 0 deletions(-)
>
> diff --git a/hw/xen_common.h b/hw/xen_common.h
> index dd54063..96cfad7 100644
> --- a/hw/xen_common.h
> +++ b/hw/xen_common.h
> @@ -53,5 +53,6 @@ typedef xc_interface *qemu_xc_interface;
>  #endif
>
>  qemu_irq *i8259_xen_init(void);
> +void destroy_hvm_domain(void);
>
>  #endif /* QEMU_HW_XEN_COMMON_H */
> diff --git a/xen-all.c b/xen-all.c
> index 4e0b061..13672f0 100644
> --- a/xen-all.c
> +++ b/xen-all.c
> @@ -8,12 +8,38 @@
>
>  #include "config.h"
>
> +#include <sys/mman.h>
> +
>  #include "hw/pci.h"
>  #include "hw/xen_common.h"
>  #include "hw/xen_backend.h"
>
>  #include "xen_mapcache.h"
>
> +#include <xen/hvm/ioreq.h>
> +
> +//#define DEBUG_XEN
> +
> +#ifdef DEBUG_XEN
> +#define DPRINTF(fmt, ...) \
> +    do { fprintf(stderr, "xen: " fmt, ## __VA_ARGS__); } while (0)
> +#else
> +#define DPRINTF(fmt, ...) \
> +    do { } while (0)
> +#endif
> +
> +shared_iopage_t *shared_page = NULL;
> +#define BUFFER_IO_MAX_DELAY  100
> +buffered_iopage_t *buffered_io_page = NULL;
> +QEMUTimer *buffered_io_timer;
> +/* the evtchn port for polling the notification, */
> +evtchn_port_t *ioreq_local_port;
> +/* the evtchn fd for polling */
> +int xce_handle = -1;
> +/* which vcpu we are serving */
> +int send_vcpu = 0;
> +long time_offset = 0;

Are all these global needed? Can some of them actually be 'static'?
Could you wrap these into a struct and pass that around?

> +
>  /* Xen specific function for piix pci */
>
>  int xen_pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num)
> @@ -111,19 +137,374 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t 
> size)
>  }
>
>
> +/* VCPU Operations, MMIO, IO ring ... */
> +
> +/* get the ioreq packets from share mem */
> +static ioreq_t *cpu_get_ioreq_from_shared_memory(int vcpu)
> +{
> +    ioreq_t *req = &shared_page->vcpu_ioreq[vcpu];
> +
> +    if (req->state != STATE_IOREQ_READY) {
> +        DPRINTF("I/O request not ready: "
> +                "%x, ptr: %x, port: %"PRIx64", "
> +                "data: %"PRIx64", count: %u, size: %u\n",
> +                req->state, req->data_is_ptr, req->addr,
> +                req->data, req->count, req->size);
> +        return NULL;
> +    }
> +
> +    xen_rmb(); /* see IOREQ_READY /then/ read contents of ioreq */
> +
> +    req->state = STATE_IOREQ_INPROCESS;
> +    return req;
> +}
> +
> +/* use poll to get the port notification */
> +/* ioreq_vec--out,the */
> +/* retval--the number of ioreq packet */
> +static ioreq_t *cpu_get_ioreq(void)
> +{
> +    int i;
> +    evtchn_port_t port;
> +
> +    port = xc_evtchn_pending(xce_handle);
> +    if (port != -1) {
> +        for ( i = 0; i < smp_cpus; i++ )

Please add braces and remove extra spaces after '(' and before ')',
also in other places.

> +            if ( ioreq_local_port[i] == port )
> +                break;
> +
> +        if ( i == smp_cpus ) {
> +            hw_error("Fatal error while trying to get io event!\n");
> +        }
> +
> +        /* unmask the wanted port again */
> +        xc_evtchn_unmask(xce_handle, port);
> +
> +        /* get the io packet from shared memory */
> +        send_vcpu = i;
> +        return cpu_get_ioreq_from_shared_memory(i);
> +    }
> +
> +    /* read error or read nothing */
> +    return NULL;
> +}
> +
> +static uint32_t do_inp(CPUState *env, pio_addr_t addr, unsigned long size)
> +{
> +    switch(size) {
> +        case 1:
> +            return cpu_inb(addr);
> +        case 2:
> +            return cpu_inw(addr);
> +        case 4:
> +            return cpu_inl(addr);
> +        default:
> +            hw_error("inp: bad size: %04"FMT_pioaddr" %lx", addr, size);
> +    }
> +}
> +
> +static void do_outp(CPUState *env, pio_addr_t addr,
> +        unsigned long size, uint32_t val)
> +{
> +    switch(size) {
> +        case 1:
> +            return cpu_outb(addr, val);
> +        case 2:
> +            return cpu_outw(addr, val);
> +        case 4:
> +            return cpu_outl(addr, val);
> +        default:
> +            hw_error("outp: bad size: %04"FMT_pioaddr" %lx", addr, size);
> +    }
> +}
> +
> +static void cpu_ioreq_pio(CPUState *env, ioreq_t *req)
> +{
> +    int i, sign;
> +
> +    sign = req->df ? -1 : 1;
> +
> +    if (req->dir == IOREQ_READ) {
> +        if (!req->data_is_ptr) {
> +            req->data = do_inp(env, req->addr, req->size);
> +        } else {
> +            uint32_t tmp;
> +
> +            for (i = 0; i < req->count; i++) {
> +                tmp = do_inp(env, req->addr, req->size);
> +                cpu_physical_memory_write(req->data + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +            }
> +        }
> +    } else if (req->dir == IOREQ_WRITE) {
> +        if (!req->data_is_ptr) {
> +            do_outp(env, req->addr, req->size, req->data);
> +        } else {
> +            for (i = 0; i < req->count; i++) {
> +                uint32_t tmp = 0;
> +
> +                cpu_physical_memory_read(req->data + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +                do_outp(env, req->addr, req->size, tmp);
> +            }
> +        }
> +    }
> +}
> +
> +static void cpu_ioreq_move(CPUState *env, ioreq_t *req)
> +{
> +    int i, sign;
> +
> +    sign = req->df ? -1 : 1;
> +
> +    if (!req->data_is_ptr) {
> +        if (req->dir == IOREQ_READ) {
> +            for (i = 0; i < req->count; i++) {
> +                cpu_physical_memory_read(req->addr + (sign * i * req->size),
> +                        (uint8_t*) &req->data, req->size);
> +            }
> +        } else if (req->dir == IOREQ_WRITE) {
> +            for (i = 0; i < req->count; i++) {
> +                cpu_physical_memory_write(req->addr + (sign * i * req->size),
> +                        (uint8_t*) &req->data, req->size);
> +            }
> +        }
> +    } else {
> +        target_ulong tmp;
> +
> +        if (req->dir == IOREQ_READ) {
> +            for (i = 0; i < req->count; i++) {
> +                cpu_physical_memory_read(req->addr + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +                cpu_physical_memory_write(req->data + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +            }
> +        } else if (req->dir == IOREQ_WRITE) {
> +            for (i = 0; i < req->count; i++) {
> +                cpu_physical_memory_read(req->data + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +                cpu_physical_memory_write(req->addr + (sign * i * req->size),
> +                        (uint8_t*) &tmp, req->size);
> +            }
> +        }
> +    }
> +}
> +
> +static void cpu_ioreq_timeoffset(CPUState *env, ioreq_t *req)
> +{
> +    /* char b[64]; */
> +
> +    time_offset += (unsigned long)req->data;
> +
> +    //DPRINTF("Time offset set %ld, added offset %"PRId64"\n",
> +            //time_offset, req->data);
> +    /* snprintf(b, 64, "%ld", time_offset); */
> +    /* xenstore_vm_write(xen_domid, "rtc/timeoffset", b); */

The commented out stuff should probably go.

> +}
> +
> +static void handle_ioreq(CPUState *env, ioreq_t *req)
> +{
> +    if (!req->data_is_ptr && (req->dir == IOREQ_WRITE) &&
> +            (req->size < sizeof(target_ulong)))
> +        req->data &= ((target_ulong)1 << (8 * req->size)) - 1;
> +
> +    switch (req->type) {
> +        case IOREQ_TYPE_PIO:
> +            cpu_ioreq_pio(env, req);
> +            break;
> +        case IOREQ_TYPE_COPY:
> +            cpu_ioreq_move(env, req);
> +            break;
> +        case IOREQ_TYPE_TIMEOFFSET:
> +            cpu_ioreq_timeoffset(env, req);
> +            break;
> +        case IOREQ_TYPE_INVALIDATE:
> +            qemu_invalidate_map_cache();
> +            break;
> +        default:
> +            hw_error("Invalid ioreq type 0x%x\n", req->type);
> +    }
> +}
> +
> +static void handle_buffered_iopage(CPUState *env)
> +{
> +    buf_ioreq_t *buf_req = NULL;
> +    ioreq_t req;
> +    int qw;
> +
> +    if (!buffered_io_page)
> +        return;
> +
> +    while (buffered_io_page->read_pointer !=
> +            buffered_io_page->write_pointer) {
> +        buf_req = &buffered_io_page->buf_ioreq[
> +            buffered_io_page->read_pointer % IOREQ_BUFFER_SLOT_NUM];
> +        req.size = 1UL << buf_req->size;
> +        req.count = 1;
> +        req.addr = buf_req->addr;
> +        req.data = buf_req->data;
> +        req.state = STATE_IOREQ_READY;
> +        req.dir = buf_req->dir;
> +        req.df = 1;
> +        req.type = buf_req->type;
> +        req.data_is_ptr = 0;
> +        qw = (req.size == 8);
> +        if (qw) {
> +            buf_req = &buffered_io_page->buf_ioreq[
> +                (buffered_io_page->read_pointer+1) % IOREQ_BUFFER_SLOT_NUM];
> +            req.data |= ((uint64_t)buf_req->data) << 32;
> +        }
> +
> +        handle_ioreq(env, &req);
> +
> +        xen_mb();
> +        buffered_io_page->read_pointer += qw ? 2 : 1;
> +    }
> +}
> +
> +static void handle_buffered_io(void *opaque)
> +{
> +    CPUState *env = opaque;
> +
> +    handle_buffered_iopage(env);
> +    qemu_mod_timer(buffered_io_timer, BUFFER_IO_MAX_DELAY +
> +                   qemu_get_clock(rt_clock));
> +}
> +
> +static void cpu_handle_ioreq(void *opaque)
> +{
> +    CPUState *env = opaque;
> +    ioreq_t *req = cpu_get_ioreq();
> +
> +    handle_buffered_iopage(env);
> +    if (req) {
> +        handle_ioreq(env, req);
> +
> +        if (req->state != STATE_IOREQ_INPROCESS) {
> +            fprintf(stderr, "Badness in I/O request ... not in service?!: "
> +                    "%x, ptr: %x, port: %"PRIx64", "
> +                    "data: %"PRIx64", count: %u, size: %u\n",
> +                    req->state, req->data_is_ptr, req->addr,
> +                    req->data, req->count, req->size);
> +            destroy_hvm_domain();
> +            return;
> +        }
> +
> +        xen_wmb(); /* Update ioreq contents /then/ update state. */
> +
> +        /*
> +         * We do this before we send the response so that the tools
> +         * have the opportunity to pick up on the reset before the
> +         * guest resumes and does a hlt with interrupts disabled which
> +         * causes Xen to powerdown the domain.
> +         */
> +        if (vm_running) {
> +            if (qemu_shutdown_requested_get()) {
> +                destroy_hvm_domain();
> +            }
> +            if (qemu_reset_requested_get()) {
> +                qemu_system_reset();
> +            }
> +        }
> +
> +        req->state = STATE_IORESP_READY;
> +        xc_evtchn_notify(xce_handle, ioreq_local_port[send_vcpu]);
> +    }
> +}
> +
> +static void xen_main_loop_prepare(void)
> +{
> +    CPUState *env = cpu_single_env;
> +
> +    int evtchn_fd = xce_handle == -1 ? -1 : xc_evtchn_fd(xce_handle);
> +
> +    buffered_io_timer = qemu_new_timer(rt_clock, handle_buffered_io,
> +                                       cpu_single_env);
> +    qemu_mod_timer(buffered_io_timer, qemu_get_clock(rt_clock));
> +
> +    if (evtchn_fd != -1)
> +        qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, env);

braces

> +}
> +
> +
>  /* Initialise Xen */
>
> +static void xen_vm_change_state_handler(void *opaque, int running, int 
> reason)
> +{
> +    if (running)

braces

> +        xen_main_loop_prepare();
> +}
> +
>  int xen_init(int smp_cpus)
>  {
> +    int i, rc;
> +    unsigned long ioreq_pfn;
> +
>     xen_xc = xc_interface_open(NULL, NULL, 0);
>     if (xen_xc == NULL) {
>         xen_be_printf(NULL, 0, "can't open xen interface\n");
>         return -1;
>     }
>
> +    xce_handle = xc_evtchn_open();
> +    if (xce_handle == -1) {
> +        perror("open");
> +        return -errno;
> +    }
> +
> +    xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_IOREQ_PFN, &ioreq_pfn);
> +    DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
> +    shared_page = xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE,
> +                                       PROT_READ|PROT_WRITE, ioreq_pfn);
> +    if (shared_page == NULL) {
> +        hw_error("map shared IO page returned error %d handle=%p", errno, 
> xen_xc);
> +    }
> +
> +    xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_BUFIOREQ_PFN, &ioreq_pfn);
> +    DPRINTF("buffered io page at pfn %lx\n", ioreq_pfn);
> +    buffered_io_page = xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE,
> +                                            PROT_READ|PROT_WRITE, ioreq_pfn);
> +    if (buffered_io_page == NULL) {
> +        hw_error("map buffered IO page returned error %d", errno);
> +    }
> +
> +    ioreq_local_port = qemu_mallocz(smp_cpus * sizeof(evtchn_port_t));
> +
> +    /* FIXME: how about if we overflow the page here? */
> +    for (i = 0; i < smp_cpus; i++) {
> +        rc = xc_evtchn_bind_interdomain(xce_handle, xen_domid,
> +                                        shared_page->vcpu_ioreq[i].vp_eport);
> +        if (rc == -1) {
> +            fprintf(stderr, "bind interdomain ioctl error %d\n", errno);
> +            return -1;
> +        }
> +        ioreq_local_port[i] = rc;
> +    }
> +
>     /* Init RAM management */
>     qemu_map_cache_init();
>     xen_ram_init(ram_size);
>
> +    qemu_add_vm_change_state_handler(xen_vm_change_state_handler, NULL);
> +
>     return 0;
>  }
> +
> +void destroy_hvm_domain(void)
> +{
> +    xc_interface *xc_handle;
> +    int sts;
> +
> +    xc_handle = xc_interface_open(NULL, NULL, 0);
> +    if (!xc_handle)
> +        fprintf(stderr, "Cannot acquire xenctrl handle\n");
> +    else {
> +        sts = xc_domain_shutdown(xc_handle, xen_domid, SHUTDOWN_poweroff);
> +        if (sts != 0)
> +            fprintf(stderr, "? xc_domain_shutdown failed to issue poweroff, "
> +                    "sts %d, errno %d\n", sts, errno);

braces, perror()