Date: Mon, 7 Jan 2013 07:33:48 +0000 (UTC) From: Peter Grehan <grehan@svn.freebsd.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r245127 - projects/bhyve/usr.sbin/bhyve Message-ID: <50ea7a5c.19f3.7682b587@svn.freebsd.org>
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Author: grehan Date: Mon Jan 7 07:33:48 2013 New Revision: 245127 URL: http://svnweb.freebsd.org/changeset/base/245127 Log: Don't completely drain the read file descriptor. Instead, only fill up to the uart's rx fifo size, and leave any remaining input for when the rx fifo is read. This allows cut'n'paste of long lines to be done into the bhyve console without truncation. Also, introduce a mutex since the file input will run in the mevent thread context and may corrupt state accessed by a vCPU thread. Reviewed by: neel Approved by: NetApp Modified: projects/bhyve/usr.sbin/bhyve/pci_uart.c Modified: projects/bhyve/usr.sbin/bhyve/pci_uart.c ============================================================================== --- projects/bhyve/usr.sbin/bhyve/pci_uart.c Mon Jan 7 07:30:41 2013 (r245126) +++ projects/bhyve/usr.sbin/bhyve/pci_uart.c Mon Jan 7 07:33:48 2013 (r245127) @@ -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, 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 vc 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 vc done: pci_uart_toggle_intr(sc); + pthread_mutex_unlock(&sc->mtx); } uint64_t @@ -479,6 +497,8 @@ pci_uart_read(struct vmctx *ctx, int vcp 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 vcp done: pci_uart_toggle_intr(sc); + pthread_mutex_unlock(&sc->mtx); + return (reg); } @@ -570,6 +592,8 @@ pci_uart_init(struct vmctx *ctx, struct 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);
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