diff options
| -rw-r--r-- | usr.sbin/bhyve/pci_uart.c | 44 |
1 files changed, 34 insertions, 10 deletions
diff --git a/usr.sbin/bhyve/pci_uart.c b/usr.sbin/bhyve/pci_uart.c index 3f192e1..dd30551 100644 --- a/usr.sbin/bhyve/pci_uart.c +++ b/usr.sbin/bhyve/pci_uart.c @@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$"); #include <unistd.h> #include <stdbool.h> #include <string.h> +#include <pthread.h> #include "bhyverun.h" #include "pci_emul.h" @@ -97,6 +98,7 @@ struct fifo { struct pci_uart_softc { struct pci_devinst *pi; + pthread_mutex_t mtx; /* protects all softc elements */ uint8_t data; /* Data register (R/W) */ uint8_t ier; /* Interrupt enable register (R/W) */ uint8_t lcr; /* Line control register (R/W) */ @@ -214,6 +216,13 @@ fifo_numchars(struct fifo *fifo) return (fifo->num); } +static int +fifo_available(struct fifo *fifo) +{ + + return (fifo->num < fifo->size); +} + static void pci_uart_opentty(struct pci_uart_softc *sc) { @@ -304,19 +313,25 @@ pci_uart_drain(int fd, enum ev_type ev, void *arg) assert(fd == STDIN_FILENO); assert(ev == EVF_READ); + + /* + * This routine is called in the context of the mevent thread + * to take out the softc lock to protect against concurrent + * access from a vCPU i/o exit + */ + pthread_mutex_lock(&sc->mtx); - while ((ch = ttyread()) != -1) { - /* - * If we are in loopback mode then drop this character. - */ - if ((sc->mcr & MCR_LOOPBACK) != 0) - continue; - - if (fifo_putchar(&sc->rxfifo, ch) != 0) - sc->lsr |= LSR_OE; + if ((sc->mcr & MCR_LOOPBACK) != 0) { + (void) ttyread(); + } else { + while (fifo_available(&sc->rxfifo) && + ((ch = ttyread()) != -1)) { + fifo_putchar(&sc->rxfifo, ch); + } + pci_uart_toggle_intr(sc); } - pci_uart_toggle_intr(sc); + pthread_mutex_unlock(&sc->mtx); } static void @@ -337,6 +352,8 @@ pci_uart_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, pci_uart_opentty(sc); sc->opened = 1; } + + pthread_mutex_lock(&sc->mtx); /* * Take care of the special case DLAB accesses first @@ -458,6 +475,7 @@ pci_uart_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, done: pci_uart_toggle_intr(sc); + pthread_mutex_unlock(&sc->mtx); } uint64_t @@ -479,6 +497,8 @@ pci_uart_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, sc->opened = 1; } + pthread_mutex_lock(&sc->mtx); + /* * Take care of the special case DLAB accesses first */ @@ -554,6 +574,8 @@ pci_uart_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, done: pci_uart_toggle_intr(sc); + pthread_mutex_unlock(&sc->mtx); + return (reg); } @@ -570,6 +592,8 @@ pci_uart_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts) pi->pi_arg = sc; sc->pi = pi; + pthread_mutex_init(&sc->mtx, NULL); + /* initialize config space */ pci_set_cfgdata16(pi, PCIR_DEVICE, COM_DEV); pci_set_cfgdata16(pi, PCIR_VENDOR, COM_VENDOR); |
