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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2] xen/console: buffer and show origin of guest PV writes
On 09/09/2013 05:13, "Ian Campbell" <Ian.Campbell@xxxxxxxxxx> wrote:
> On Mon, 2013-09-09 at 04:13 -0700, Keir Fraser wrote:
>> On 16/08/2013 20:01, "Daniel De Graaf" <dgdegra@xxxxxxxxxxxxx> wrote:
>>
>>> Guests other than domain 0 using the console output have previously been
>>> controlled by the VERBOSE define, but with no designation of which
>>> guest's output was on the console. This patch converts the HVM output
>>> buffering to be used by all domains, line buffering their output and
>>> prefixing it with the domain ID. This is especially useful for debugging
>>> stub domains.
>>>
>>> Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
>>
>> This seems good, but, if we process and buffer dom0's output, we lose the
>> possibility of running a terminal session in dom0 over the Xen console.
>> Personally I do that quite a bit -- serial access only, get Xen's debugging
>> there, but also can log in to dom0. Does noone else??
>
> I think I do too, I'm more likely to on ARM as well since there is often
> only a single debug serial port and no graphics.
>
> Oh, doesn't code like:
>> + if ( is_hardware_domain(cd) )
>>> + {
>>> + /* Use direct console output as it could be interactive */
>>> + spin_lock_irq(&console_lock);
>>> +
>>> + sercon_puts(kbuf);
>>> + video_puts(kbuf);
>
> ...mean that Daniel has already done the right thing for dom0 here?
Ah, you could be right. Well if he will confirm that then I will give my
Ack.
-- Keir
>>
>> -- Keir
>>
>>> ---
>>>
>>> Changes since v1 (RFC):
>>> - Use prefix of (d%d) in place of (XEN) for both PV and HVM output
>>> - Guests other than dom0 have non-printable characters stripped
>>> - Use unsigned type for pbuf_idx
>>> - Formatting fixes
>>>
>>> xen/arch/x86/hvm/hvm.c | 27 +++++-------
>>> xen/common/domain.c | 8 ++++
>>> xen/drivers/char/console.c | 94
>>> ++++++++++++++++++++++++++++++++--------
>>> xen/include/asm-x86/hvm/domain.h | 6 ---
>>> xen/include/xen/lib.h | 2 +
>>> xen/include/xen/sched.h | 6 +++
>>> 6 files changed, 103 insertions(+), 40 deletions(-)
>>>
>>> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
>>> index 1fcaed0..4ff76cc 100644
>>> --- a/xen/arch/x86/hvm/hvm.c
>>> +++ b/xen/arch/x86/hvm/hvm.c
>>> @@ -485,8 +485,7 @@ static int hvm_set_ioreq_page(
>>> static int hvm_print_line(
>>> int dir, uint32_t port, uint32_t bytes, uint32_t *val)
>>> {
>>> - struct vcpu *curr = current;
>>> - struct hvm_domain *hd = &curr->domain->arch.hvm_domain;
>>> + struct domain *cd = current->domain;
>>> char c = *val;
>>>
>>> BUG_ON(bytes != 1);
>>> @@ -495,17 +494,16 @@ static int hvm_print_line(
>>> if ( !isprint(c) && (c != '\n') && (c != '\t') )
>>> return X86EMUL_OKAY;
>>>
>>> - spin_lock(&hd->pbuf_lock);
>>> - hd->pbuf[hd->pbuf_idx++] = c;
>>> - if ( (hd->pbuf_idx == (HVM_PBUF_SIZE - 2)) || (c == '\n') )
>>> + spin_lock(&cd->pbuf_lock);
>>> + if ( c != '\n' )
>>> + cd->pbuf[cd->pbuf_idx++] = c;
>>> + if ( (cd->pbuf_idx == (DOMAIN_PBUF_SIZE - 1)) || (c == '\n') )
>>> {
>>> - if ( c != '\n' )
>>> - hd->pbuf[hd->pbuf_idx++] = '\n';
>>> - hd->pbuf[hd->pbuf_idx] = '\0';
>>> - printk(XENLOG_G_DEBUG "HVM%u: %s", curr->domain->domain_id,
>>> hd->pbuf);
>>> - hd->pbuf_idx = 0;
>>> + cd->pbuf[cd->pbuf_idx] = '\0';
>>> + guest_printk(cd, XENLOG_G_DEBUG "%s\n", cd->pbuf);
>>> + cd->pbuf_idx = 0;
>>> }
>>> - spin_unlock(&hd->pbuf_lock);
>>> + spin_unlock(&cd->pbuf_lock);
>>>
>>> return X86EMUL_OKAY;
>>> }
>>> @@ -521,19 +519,16 @@ int hvm_domain_initialise(struct domain *d)
>>> return -EINVAL;
>>> }
>>>
>>> - spin_lock_init(&d->arch.hvm_domain.pbuf_lock);
>>> spin_lock_init(&d->arch.hvm_domain.irq_lock);
>>> spin_lock_init(&d->arch.hvm_domain.uc_lock);
>>>
>>> INIT_LIST_HEAD(&d->arch.hvm_domain.msixtbl_list);
>>> spin_lock_init(&d->arch.hvm_domain.msixtbl_list_lock);
>>>
>>> - d->arch.hvm_domain.pbuf = xzalloc_array(char, HVM_PBUF_SIZE);
>>> d->arch.hvm_domain.params = xzalloc_array(uint64_t, HVM_NR_PARAMS);
>>> d->arch.hvm_domain.io_handler = xmalloc(struct hvm_io_handler);
>>> rc = -ENOMEM;
>>> - if ( !d->arch.hvm_domain.pbuf || !d->arch.hvm_domain.params ||
>>> - !d->arch.hvm_domain.io_handler )
>>> + if ( !d->arch.hvm_domain.params || !d->arch.hvm_domain.io_handler )
>>> goto fail0;
>>> d->arch.hvm_domain.io_handler->num_slot = 0;
>>>
>>> @@ -578,7 +573,6 @@ int hvm_domain_initialise(struct domain *d)
>>> fail0:
>>> xfree(d->arch.hvm_domain.io_handler);
>>> xfree(d->arch.hvm_domain.params);
>>> - xfree(d->arch.hvm_domain.pbuf);
>>> return rc;
>>> }
>>>
>>> @@ -603,7 +597,6 @@ void hvm_domain_relinquish_resources(struct domain *d)
>>>
>>> xfree(d->arch.hvm_domain.io_handler);
>>> xfree(d->arch.hvm_domain.params);
>>> - xfree(d->arch.hvm_domain.pbuf);
>>> }
>>>
>>> void hvm_domain_destroy(struct domain *d)
>>> diff --git a/xen/common/domain.c b/xen/common/domain.c
>>> index 6c264a5..daac2c9 100644
>>> --- a/xen/common/domain.c
>>> +++ b/xen/common/domain.c
>>> @@ -231,6 +231,8 @@ struct domain *domain_create(
>>> spin_lock_init(&d->shutdown_lock);
>>> d->shutdown_code = -1;
>>>
>>> + spin_lock_init(&d->pbuf_lock);
>>> +
>>> err = -ENOMEM;
>>> if ( !zalloc_cpumask_var(&d->domain_dirty_cpumask) )
>>> goto fail;
>>> @@ -286,6 +288,10 @@ struct domain *domain_create(
>>> d->mem_event = xzalloc(struct mem_event_per_domain);
>>> if ( !d->mem_event )
>>> goto fail;
>>> +
>>> + d->pbuf = xzalloc_array(char, DOMAIN_PBUF_SIZE);
>>> + if ( !d->pbuf )
>>> + goto fail;
>>> }
>>>
>>> if ( (err = arch_domain_create(d, domcr_flags)) != 0 )
>>> @@ -318,6 +324,7 @@ struct domain *domain_create(
>>> d->is_dying = DOMDYING_dead;
>>> atomic_set(&d->refcnt, DOMAIN_DESTROYED);
>>> xfree(d->mem_event);
>>> + xfree(d->pbuf);
>>> if ( init_status & INIT_arch )
>>> arch_domain_destroy(d);
>>> if ( init_status & INIT_gnttab )
>>> @@ -730,6 +737,7 @@ static void complete_domain_destroy(struct rcu_head
>>> *head)
>>> #endif
>>>
>>> xfree(d->mem_event);
>>> + xfree(d->pbuf);
>>>
>>> for ( i = d->max_vcpus - 1; i >= 0; i-- )
>>> if ( (v = d->vcpu[i]) != NULL )
>>> diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
>>> index 8ac32e4..b8d9a9f 100644
>>> --- a/xen/drivers/char/console.c
>>> +++ b/xen/drivers/char/console.c
>>> @@ -24,6 +24,7 @@
>>> #include <xen/shutdown.h>
>>> #include <xen/video.h>
>>> #include <xen/kexec.h>
>>> +#include <xen/ctype.h>
>>> #include <asm/debugger.h>
>>> #include <asm/div64.h>
>>> #include <xen/hypercall.h> /* for do_console_io */
>>> @@ -375,6 +376,7 @@ static long
>>> guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer, int count)
>>> {
>>> char kbuf[128];
>>> int kcount;
>>> + struct domain *cd = current->domain;
>>>
>>> while ( count > 0 )
>>> {
>>> @@ -388,19 +390,60 @@ static long
>>> guest_console_write(XEN_GUEST_HANDLE_PARAM(char) buffer, int count)
>>> return -EFAULT;
>>> kbuf[kcount] = '\0';
>>>
>>> - spin_lock_irq(&console_lock);
>>> + if ( is_hardware_domain(cd) )
>>> + {
>>> + /* Use direct console output as it could be interactive */
>>> + spin_lock_irq(&console_lock);
>>> +
>>> + sercon_puts(kbuf);
>>> + video_puts(kbuf);
>>>
>>> - sercon_puts(kbuf);
>>> - video_puts(kbuf);
>>> + if ( opt_console_to_ring )
>>> + {
>>> + conring_puts(kbuf);
>>> + tasklet_schedule(¬ify_dom0_con_ring_tasklet);
>>> + }
>>>
>>> - if ( opt_console_to_ring )
>>> + spin_unlock_irq(&console_lock);
>>> + }
>>> + else
>>> {
>>> - conring_puts(kbuf);
>>> - tasklet_schedule(¬ify_dom0_con_ring_tasklet);
>>> + char *kin = kbuf;
>>> + char *kout = kbuf;
>>> + char c;
>>> + /* Strip non-printable characters */
>>> + for ( ; ; )
>>> + {
>>> + c = *kin++;
>>> + if ( c == '\0' || c == '\n' )
>>> + break;
>>> + if ( isprint(c) || c == '\t' )
>>> + *kout++ = c;
>>> + }
>>> + *kout = '\0';
>>> + spin_lock(&cd->pbuf_lock);
>>> + if ( c == '\n' )
>>> + {
>>> + kcount = kin - kbuf;
>>> + cd->pbuf[cd->pbuf_idx] = '\0';
>>> + guest_printk(cd, XENLOG_G_DEBUG "%s%s\n", cd->pbuf, kbuf);
>>> + cd->pbuf_idx = 0;
>>> + }
>>> + else if ( cd->pbuf_idx + kcount < (DOMAIN_PBUF_SIZE - 1) )
>>> + {
>>> + /* buffer the output until a newline */
>>> + memcpy(cd->pbuf + cd->pbuf_idx, kbuf, kcount);
>>> + cd->pbuf_idx += kcount;
>>> + }
>>> + else
>>> + {
>>> + cd->pbuf[cd->pbuf_idx] = '\0';
>>> + guest_printk(cd, XENLOG_G_DEBUG "%s%s\n", cd->pbuf, kbuf);
>>> + cd->pbuf_idx = 0;
>>> + }
>>> + spin_unlock(&cd->pbuf_lock);
>>> }
>>>
>>> - spin_unlock_irq(&console_lock);
>>> -
>>> guest_handle_add_offset(buffer, kcount);
>>> count -= kcount;
>>> }
>>> @@ -504,12 +547,12 @@ static int printk_prefix_check(char *p, char **pp)
>>> ((loglvl < upper_thresh) && printk_ratelimit()));
>>> }
>>>
>>> -static void printk_start_of_line(void)
>>> +static void printk_start_of_line(const char *prefix)
>>> {
>>> struct tm tm;
>>> char tstr[32];
>>>
>>> - __putstr("(XEN) ");
>>> + __putstr(prefix);
>>>
>>> if ( !opt_console_timestamps )
>>> return;
>>> @@ -524,12 +567,11 @@ static void printk_start_of_line(void)
>>> __putstr(tstr);
>>> }
>>>
>>> -void printk(const char *fmt, ...)
>>> +static void vprintk_common(const char *prefix, const char *fmt, va_list
>>> args)
>>> {
>>> static char buf[1024];
>>> static int start_of_line = 1, do_print;
>>>
>>> - va_list args;
>>> char *p, *q;
>>> unsigned long flags;
>>>
>>> @@ -537,9 +579,7 @@ void printk(const char *fmt, ...)
>>> local_irq_save(flags);
>>> spin_lock_recursive(&console_lock);
>>>
>>> - va_start(args, fmt);
>>> (void)vsnprintf(buf, sizeof(buf), fmt, args);
>>> - va_end(args);
>>>
>>> p = buf;
>>>
>>> @@ -551,7 +591,7 @@ void printk(const char *fmt, ...)
>>> if ( do_print )
>>> {
>>> if ( start_of_line )
>>> - printk_start_of_line();
>>> + printk_start_of_line(prefix);
>>> __putstr(p);
>>> __putstr("\n");
>>> }
>>> @@ -566,7 +606,7 @@ void printk(const char *fmt, ...)
>>> if ( do_print )
>>> {
>>> if ( start_of_line )
>>> - printk_start_of_line();
>>> + printk_start_of_line(prefix);
>>> __putstr(p);
>>> }
>>> start_of_line = 0;
>>> @@ -576,6 +616,26 @@ void printk(const char *fmt, ...)
>>> local_irq_restore(flags);
>>> }
>>>
>>> +void printk(const char *fmt, ...)
>>> +{
>>> + va_list args;
>>> + va_start(args, fmt);
>>> + vprintk_common("(XEN) ", fmt, args);
>>> + va_end(args);
>>> +}
>>> +
>>> +void guest_printk(struct domain *d, const char *fmt, ...)
>>> +{
>>> + va_list args;
>>> + char prefix[16];
>>> +
>>> + snprintf(prefix, sizeof(prefix), "(d%d) ", d->domain_id);
>>> +
>>> + va_start(args, fmt);
>>> + vprintk_common(prefix, fmt, args);
>>> + va_end(args);
>>> +}
>>> +
>>> void __init console_init_preirq(void)
>>> {
>>> char *p;
>>> @@ -791,7 +851,7 @@ int __printk_ratelimit(int ratelimit_ms, int
>>> ratelimit_burst)
>>> snprintf(lost_str, sizeof(lost_str), "%d", lost);
>>> /* console_lock may already be acquired by printk(). */
>>> spin_lock_recursive(&console_lock);
>>> - printk_start_of_line();
>>> + printk_start_of_line("(XEN) ");
>>> __putstr("printk: ");
>>> __putstr(lost_str);
>>> __putstr(" messages suppressed.\n");
>>> diff --git a/xen/include/asm-x86/hvm/domain.h
>>> b/xen/include/asm-x86/hvm/domain.h
>>> index 27b3de5..b1e3187 100644
>>> --- a/xen/include/asm-x86/hvm/domain.h
>>> +++ b/xen/include/asm-x86/hvm/domain.h
>>> @@ -62,12 +62,6 @@ struct hvm_domain {
>>> /* emulated irq to pirq */
>>> struct radix_tree_root emuirq_pirq;
>>>
>>> - /* hvm_print_line() logging. */
>>> -#define HVM_PBUF_SIZE 80
>>> - char *pbuf;
>>> - int pbuf_idx;
>>> - spinlock_t pbuf_lock;
>>> -
>>> uint64_t *params;
>>>
>>> /* Memory ranges with pinned cache attributes. */
>>> diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
>>> index 74b34eb..40afe12 100644
>>> --- a/xen/include/xen/lib.h
>>> +++ b/xen/include/xen/lib.h
>>> @@ -83,6 +83,8 @@ extern void debugtrace_printk(const char *fmt, ...);
>>> #define _p(_x) ((void *)(unsigned long)(_x))
>>> extern void printk(const char *format, ...)
>>> __attribute__ ((format (printf, 1, 2)));
>>> +extern void guest_printk(struct domain *d, const char *format, ...)
>>> + __attribute__ ((format (printf, 2, 3)));
>>> extern void panic(const char *format, ...)
>>> __attribute__ ((format (printf, 1, 2)));
>>> extern long vm_assist(struct domain *, unsigned int, unsigned int);
>>> diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
>>> index ae6a3b8..0013a8d 100644
>>> --- a/xen/include/xen/sched.h
>>> +++ b/xen/include/xen/sched.h
>>> @@ -341,6 +341,12 @@ struct domain
>>> /* Control-plane tools handle for this domain. */
>>> xen_domain_handle_t handle;
>>>
>>> + /* hvm_print_line() and guest_console_write() logging. */
>>> +#define DOMAIN_PBUF_SIZE 80
>>> + char *pbuf;
>>> + unsigned pbuf_idx;
>>> + spinlock_t pbuf_lock;
>>> +
>>> /* OProfile support. */
>>> struct xenoprof *xenoprof;
>>> int32_t time_offset_seconds;
>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxx
>> http://lists.xen.org/xen-devel
>
>
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