[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.10] x86/guest: add PV console code
commit 7477359b9a462d066a4819cefb6d6e60bc4defc5 Author: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> AuthorDate: Fri Nov 24 11:07:32 2017 +0000 Commit: Roger Pau Monne <roger.pau@xxxxxxxxxx> CommitDate: Thu Jan 11 17:51:19 2018 +0000 x86/guest: add PV console code Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx> --- xen/drivers/char/Makefile | 1 + xen/drivers/char/xen_pv_console.c | 205 ++++++++++++++++++++++++++++++++++ xen/include/asm-x86/fixmap.h | 1 + xen/include/asm-x86/guest/hypercall.h | 33 ++++++ xen/include/xen/pv_console.h | 32 ++++++ 5 files changed, 272 insertions(+) diff --git a/xen/drivers/char/Makefile b/xen/drivers/char/Makefile index aa169d7961..9d48d0f2dc 100644 --- a/xen/drivers/char/Makefile +++ b/xen/drivers/char/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_HAS_SCIF) += scif-uart.o obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o obj-$(CONFIG_ARM) += arm-uart.o obj-y += serial.o +obj-$(CONFIG_XEN_GUEST) += xen_pv_console.o diff --git a/xen/drivers/char/xen_pv_console.c b/xen/drivers/char/xen_pv_console.c new file mode 100644 index 0000000000..f5aca4c69e --- /dev/null +++ b/xen/drivers/char/xen_pv_console.c @@ -0,0 +1,205 @@ +/****************************************************************************** + * drivers/char/xen_pv_console.c + * + * A frontend driver for Xen's PV console. + * Can be used when Xen is running on top of Xen in pv-in-pvh mode. + * (Linux's name for this is hvc console) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; If not, see <http://www.gnu.org/licenses/>. + * + * Copyright (c) 2017 Citrix Systems Ltd. + */ + +#include <xen/lib.h> +#include <xen/hypercall.h> +#include <xen/pv_console.h> + +#include <asm/fixmap.h> +#include <asm/guest.h> + +#include <public/io/console.h> + +static struct xencons_interface *cons_ring; +static evtchn_port_t cons_evtchn; +static serial_rx_fn cons_rx_handler; +static DEFINE_SPINLOCK(tx_lock); + +void __init pv_console_init(void) +{ + long r; + uint64_t raw_pfn = 0, raw_evtchn = 0; + + if ( !xen_guest ) + { + printk("PV console init failed: xen_guest mode is not active!\n"); + return; + } + + r = xen_hypercall_hvm_get_param(HVM_PARAM_CONSOLE_PFN, &raw_pfn); + if ( r < 0 ) + goto error; + + r = xen_hypercall_hvm_get_param(HVM_PARAM_CONSOLE_EVTCHN, &raw_evtchn); + if ( r < 0 ) + goto error; + + set_fixmap(FIX_PV_CONSOLE, raw_pfn << PAGE_SHIFT); + cons_ring = (struct xencons_interface *)fix_to_virt(FIX_PV_CONSOLE); + cons_evtchn = raw_evtchn; + + printk("Initialised PV console at 0x%p with pfn %#lx and evtchn %#x\n", + cons_ring, raw_pfn, cons_evtchn); + return; + + error: + printk("Couldn't initialise PV console\n"); +} + +void __init pv_console_set_rx_handler(serial_rx_fn fn) +{ + cons_rx_handler = fn; +} + +void __init pv_console_init_postirq(void) +{ + if ( !cons_ring ) + return; + + xen_hypercall_evtchn_unmask(cons_evtchn); +} + +static void notify_daemon(void) +{ + xen_hypercall_evtchn_send(cons_evtchn); +} + +size_t pv_console_rx(struct cpu_user_regs *regs) +{ + char c; + XENCONS_RING_IDX cons, prod; + size_t recv = 0; + + if ( !cons_ring ) + return 0; + + /* TODO: move this somewhere */ + if ( !test_bit(cons_evtchn, XEN_shared_info->evtchn_pending) ) + return 0; + + prod = ACCESS_ONCE(cons_ring->in_prod); + cons = cons_ring->in_cons; + + /* + * Latch pointers before accessing the ring. Included compiler barrier also + * ensures that pointers are really read only once into local variables. + */ + smp_rmb(); + + ASSERT((prod - cons) <= sizeof(cons_ring->in)); + + while ( cons != prod ) + { + c = cons_ring->in[MASK_XENCONS_IDX(cons++, cons_ring->in)]; + if ( cons_rx_handler ) + cons_rx_handler(c, regs); + recv++; + } + + /* No need for a mem barrier because every character was already consumed */ + barrier(); + ACCESS_ONCE(cons_ring->in_cons) = cons; + notify_daemon(); + + clear_bit(cons_evtchn, XEN_shared_info->evtchn_pending); + + return recv; +} + +static size_t pv_ring_puts(const char *buf) +{ + XENCONS_RING_IDX cons, prod; + size_t sent = 0, avail; + bool put_r = false; + + while ( buf[sent] != '\0' || put_r ) + { + cons = ACCESS_ONCE(cons_ring->out_cons); + prod = cons_ring->out_prod; + + /* + * Latch pointers before accessing the ring. Included compiler barrier + * ensures that pointers are really read only once into local variables. + */ + smp_rmb(); + + ASSERT((prod - cons) <= sizeof(cons_ring->out)); + avail = sizeof(cons_ring->out) - (prod - cons); + + if ( avail == 0 ) + { + /* Wait for xenconsoled to consume our output */ + xen_hypercall_sched_op(SCHEDOP_yield, NULL); + continue; + } + + while ( avail && (buf[sent] != '\0' || put_r) ) + { + if ( put_r ) + { + cons_ring->out[MASK_XENCONS_IDX(prod++, cons_ring->out)] = '\r'; + put_r = false; + } + else + { + cons_ring->out[MASK_XENCONS_IDX(prod++, cons_ring->out)] = + buf[sent]; + + /* Send '\r' for every '\n' */ + if ( buf[sent] == '\n' ) + put_r = true; + sent++; + } + avail--; + } + + /* Write to the ring before updating the pointer */ + smp_wmb(); + ACCESS_ONCE(cons_ring->out_prod) = prod; + notify_daemon(); + } + + return sent; +} + +void pv_console_puts(const char *buf) +{ + unsigned long flags; + + if ( !cons_ring ) + return; + + spin_lock_irqsave(&tx_lock, flags); + pv_ring_puts(buf); + spin_unlock_irqrestore(&tx_lock, flags); +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index ded4ddf21b..16ccaa2c77 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -46,6 +46,7 @@ enum fixed_addresses { FIX_COM_END, FIX_EHCI_DBGP, #ifdef CONFIG_XEN_GUEST + FIX_PV_CONSOLE, FIX_XEN_SHARED_INFO, #endif /* CONFIG_XEN_GUEST */ /* Everything else should go further down. */ diff --git a/xen/include/asm-x86/guest/hypercall.h b/xen/include/asm-x86/guest/hypercall.h index b36a1cc189..81a955d479 100644 --- a/xen/include/asm-x86/guest/hypercall.h +++ b/xen/include/asm-x86/guest/hypercall.h @@ -105,6 +105,11 @@ static inline int xen_hypercall_vcpu_op(unsigned int cmd, unsigned int vcpu, return _hypercall64_3(long, __HYPERVISOR_vcpu_op, cmd, vcpu, arg); } +static inline long xen_hypercall_event_channel_op(unsigned int cmd, void *arg) +{ + return _hypercall64_2(long, __HYPERVISOR_event_channel_op, cmd, arg); +} + static inline long xen_hypercall_hvm_op(unsigned int op, void *arg) { return _hypercall64_2(long, __HYPERVISOR_hvm_op, op, arg); @@ -126,6 +131,34 @@ static inline long xen_hypercall_shutdown(unsigned int reason) return xen_hypercall_sched_op(SCHEDOP_shutdown, &s); } +static inline long xen_hypercall_evtchn_send(evtchn_port_t port) +{ + struct evtchn_send send = { .port = port }; + + return xen_hypercall_event_channel_op(EVTCHNOP_send, &send); +} + +static inline long xen_hypercall_evtchn_unmask(evtchn_port_t port) +{ + struct evtchn_unmask unmask = { .port = port }; + + return xen_hypercall_event_channel_op(EVTCHNOP_unmask, &unmask); +} + +static inline long xen_hypercall_hvm_get_param(uint32_t index, uint64_t *value) +{ + struct xen_hvm_param xhv = { + .domid = DOMID_SELF, + .index = index, + }; + long ret = xen_hypercall_hvm_op(HVMOP_get_param, &xhv); + + if ( ret == 0 ) + *value = xhv.value; + + return ret; +} + static inline long xen_hypercall_set_evtchn_upcall_vector( unsigned int cpu, unsigned int vector) { diff --git a/xen/include/xen/pv_console.h b/xen/include/xen/pv_console.h new file mode 100644 index 0000000000..e578b56620 --- /dev/null +++ b/xen/include/xen/pv_console.h @@ -0,0 +1,32 @@ +#ifndef __XEN_PV_CONSOLE_H__ +#define __XEN_PV_CONSOLE_H__ + +#include <xen/serial.h> + +#ifdef CONFIG_XEN_GUEST + +void pv_console_init(void); +void pv_console_set_rx_handler(serial_rx_fn fn); +void pv_console_init_postirq(void); +void pv_console_puts(const char *buf); +size_t pv_console_rx(struct cpu_user_regs *regs); + +#else + +static inline void pv_console_init(void) {} +static inline void pv_console_set_rx_handler(serial_rx_fn fn) { } +static inline void pv_console_init_postirq(void) { } +static inline void pv_console_puts(const char *buf) { } +static inline size_t pv_console_rx(struct cpu_user_regs *regs) { return 0; } + +#endif /* !CONFIG_XEN_GUEST */ +#endif /* __XEN_PV_CONSOLE_H__ */ +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.10 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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