[libvirt] [PATCH v2] libxl: load on FreeBSD

The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load. There's no procfs interface in Xen on FreeBSD, so this check always fails. In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr" #define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored" /* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL; /* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; } - if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist"); return ret; } -- 2.3.7

On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/ ACK with that changed.
return ret; }
-- 2.3.7
-- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list

On 05/27/2015 09:06 AM, Martin Kletzander wrote:
On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
ACK with that changed.
For the record, I tested this on Linux. Looks good with Martin's comment addressed. Regards, Jim

Jim Fehlig wrote:
On 05/27/2015 09:06 AM, Martin Kletzander wrote:
On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
ACK with that changed.
For the record, I tested this on Linux. Looks good with Martin's comment addressed.
Regards, Jim
Thanks for giving it a test! Is this safe to push during the freeze? Roman Bogorodskiy

On Thu, May 28, 2015 at 11:11:06AM +0400, Roman Bogorodskiy wrote:
Jim Fehlig wrote:
On 05/27/2015 09:06 AM, Martin Kletzander wrote:
On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
ACK with that changed.
For the record, I tested this on Linux. Looks good with Martin's comment addressed.
Regards, Jim
Thanks for giving it a test!
Is this safe to push during the freeze?
I also tried it before ACKing on XEN-enabled linux (made sure there is no /dev/xen/xenstored so it doesn't collide), so I'd say it's fine with me.

Martin Kletzander wrote:
On Thu, May 28, 2015 at 11:11:06AM +0400, Roman Bogorodskiy wrote:
Jim Fehlig wrote:
On 05/27/2015 09:06 AM, Martin Kletzander wrote:
On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
ACK with that changed.
For the record, I tested this on Linux. Looks good with Martin's comment addressed.
Regards, Jim
Thanks for giving it a test!
Is this safe to push during the freeze?
I also tried it before ACKing on XEN-enabled linux (made sure there is no /dev/xen/xenstored so it doesn't collide), so I'd say it's fine with me.
Last few days were quite busy for me, so I didn't push this and decided that it's too late now. I'll wait for the freeze to finish and push that, there's no rush. Meanwhile, probably I'll be able to find FreeBSD testers for libvirt/libxl to get it more tested for the next release. Thanks, Roman Bogorodskiy

Roman Bogorodskiy wrote:
Martin Kletzander wrote:
On Thu, May 28, 2015 at 11:11:06AM +0400, Roman Bogorodskiy wrote:
Jim Fehlig wrote:
On 05/27/2015 09:06 AM, Martin Kletzander wrote:
On Sun, May 24, 2015 at 06:45:02PM +0300, Roman Bogorodskiy wrote:
The libxl tries to check if it's running in dom0 by parsing /proc/xen/capabilities and if that fails it doesn't load.
There's no procfs interface in Xen on FreeBSD, so this check always fails.
In addition to checking procfs, check if /dev/xen/xenstored, that's enough to check if we're running in dom0 in FreeBSD case. --- src/libxl/libxl_driver.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-)
diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index 12be816..fddafa1 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -74,6 +74,7 @@ VIR_LOG_INIT("libxl.libxl_driver"); #define LIBXL_CONFIG_FORMAT_SEXPR "xen-sxpr"
#define HYPERVISOR_CAPABILITIES "/proc/xen/capabilities" +#define HYPERVISOR_XENSTORED "/dev/xen/xenstored"
/* Number of Xen scheduler parameters */ #define XEN_SCHED_CREDIT_NPARAM 2 @@ -427,8 +428,6 @@ static bool libxlDriverShouldLoad(bool privileged) { bool ret = false; - int status; - char *output = NULL;
/* Don't load if non-root */ if (!privileged) { @@ -436,24 +435,27 @@ libxlDriverShouldLoad(bool privileged) return ret; }
- if (!virFileExists(HYPERVISOR_CAPABILITIES)) { - VIR_INFO("Disabling driver as " HYPERVISOR_CAPABILITIES - " does not exist"); - return ret; - } - /* - * Don't load if not running on a Xen control domain (dom0). It is not - * sufficient to check for the file to exist as any guest can mount - * xenfs to /proc/xen. - */ - status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); - if (status >= 0) - status = strncmp(output, "control_d", 9); - VIR_FREE(output); - if (status) { - VIR_INFO("No Xen capabilities detected, probably not running " - "in a Xen Dom0. Disabling libxenlight driver"); - + if (virFileExists(HYPERVISOR_CAPABILITIES)) { + int status; + char *output = NULL; + /* + * Don't load if not running on a Xen control domain (dom0). It is not + * sufficient to check for the file to exist as any guest can mount + * xenfs to /proc/xen. + */ + status = virFileReadAll(HYPERVISOR_CAPABILITIES, 10, &output); + if (status >= 0) + status = strncmp(output, "control_d", 9); + VIR_FREE(output); + if (status) { + VIR_INFO("No Xen capabilities detected, probably not running " + "in a Xen Dom0. Disabling libxenlight driver"); + + return ret; + } + } else if (!virFileExists(HYPERVISOR_XENSTORED)) { + VIR_INFO("Disabling driver as neither " HYPERVISOR_CAPABILITIES + " nor " HYPERVISOR_CAPABILITIES " exist");
s/HYPERVISOR_CAPABILITIES/HYPERVISOR_XENSTORED/
ACK with that changed.
For the record, I tested this on Linux. Looks good with Martin's comment addressed.
Regards, Jim
Thanks for giving it a test!
Is this safe to push during the freeze?
I also tried it before ACKing on XEN-enabled linux (made sure there is no /dev/xen/xenstored so it doesn't collide), so I'd say it's fine with me.
Last few days were quite busy for me, so I didn't push this and decided that it's too late now. I'll wait for the freeze to finish and push that, there's no rush. Meanwhile, probably I'll be able to find FreeBSD testers for libvirt/libxl to get it more tested for the next release.
Thanks,
Roman Bogorodskiy
Pushed. Roman Bogorodskiy
participants (3)
-
Jim Fehlig
-
Martin Kletzander
-
Roman Bogorodskiy