diff mbox

[v4,07/24] xen/arm: Xen detection and shared_info page mapping

Message ID 1347621207-11294-7-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive)
State New, archived
Headers show

Commit Message

Stefano Stabellini Sept. 14, 2012, 11:13 a.m. UTC
Check for a node in the device tree compatible with "xen,xen", if it is
present set xen_domain_type to XEN_HVM_DOMAIN and continue
initialization.

Map the real shared info page using XENMEM_add_to_physmap with
XENMAPSPACE_shared_info.

Changes in v4:

- simpler parsing of Xen version in the compatible DT node.

Changes in v3:

- use the "xen,xen" notation rather than "arm,xen";
- add an additional check on the presence of the Xen version.

Changes in v2:

- replace pr_info with pr_debug.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/arm/xen/enlighten.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 61 insertions(+), 0 deletions(-)

Comments

Konrad Rzeszutek Wilk Sept. 14, 2012, 1:08 p.m. UTC | #1
On Fri, Sep 14, 2012 at 12:13:09PM +0100, Stefano Stabellini wrote:
> Check for a node in the device tree compatible with "xen,xen", if it is
> present set xen_domain_type to XEN_HVM_DOMAIN and continue
> initialization.
> 
> Map the real shared info page using XENMEM_add_to_physmap with
> XENMAPSPACE_shared_info.
> 
> Changes in v4:
> 
> - simpler parsing of Xen version in the compatible DT node.
> 
> Changes in v3:
> 
> - use the "xen,xen" notation rather than "arm,xen";
> - add an additional check on the presence of the Xen version.
> 
> Changes in v2:
> 
> - replace pr_info with pr_debug.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 61 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index c535540..6a0217d 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -5,6 +5,9 @@
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_address.h>
>  
>  struct start_info _xen_start_info;
>  struct start_info *xen_start_info = &_xen_start_info;
> @@ -33,3 +36,61 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
>  	return -ENOSYS;
>  }
>  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> +
> +/*
> + * see Documentation/devicetree/bindings/arm/xen.txt for the
> + * documentation of the Xen Device Tree format.
> + */
> +static int __init xen_guest_init(void)
> +{
> +	struct xen_add_to_physmap xatp;
> +	static struct shared_info *shared_info_page = 0;
> +	struct device_node *node;
> +	int len;
> +	const char *s = NULL;
> +	const char *version = NULL;
> +	const char *xen_prefix = "xen,xen-";
> +
> +	node = of_find_compatible_node(NULL, NULL, "xen,xen");
> +	if (!node) {
> +		pr_debug("No Xen support\n");
> +		return 0;
> +	}
> +	s = of_get_property(node, "compatible", &len);
> +	if (strlen(xen_prefix) + 3  < len &&
> +			!strncmp(xen_prefix, s, strlen(xen_prefix)))

If we have version '4.3.1' won't this trip us over?

Or if we only have 'major' and 'minor', then won't '4.11' trip us
over too?


> +		version = s + strlen(xen_prefix);
> +	if (version == NULL) {
> +		pr_debug("Xen version not found\n");
> +		return 0;
> +	}
> +	xen_domain_type = XEN_HVM_DOMAIN;
> +
> +	if (!shared_info_page)
> +		shared_info_page = (struct shared_info *)
> +			get_zeroed_page(GFP_KERNEL);
> +	if (!shared_info_page) {
> +		pr_err("not enough memory\n");
> +		return -ENOMEM;
> +	}
> +	xatp.domid = DOMID_SELF;
> +	xatp.idx = 0;
> +	xatp.space = XENMAPSPACE_shared_info;
> +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> +		BUG();
> +
> +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> +
> +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> +	 * page, we use it in the event channel upcall and in some pvclock
> +	 * related functions. We don't need the vcpu_info placement
> +	 * optimizations because we don't use any pv_mmu or pv_irq op on
> +	 * HVM.
> +	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
> +	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
> +	 * for secondary CPUs as they are brought up. */
> +	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
> +	return 0;
> +}
> +core_initcall(xen_guest_init);
> -- 
> 1.7.2.5
Stefano Stabellini Sept. 14, 2012, 2:44 p.m. UTC | #2
On Fri, 14 Sep 2012, Konrad Rzeszutek Wilk wrote:
> On Fri, Sep 14, 2012 at 12:13:09PM +0100, Stefano Stabellini wrote:
> > Check for a node in the device tree compatible with "xen,xen", if it is
> > present set xen_domain_type to XEN_HVM_DOMAIN and continue
> > initialization.
> > 
> > Map the real shared info page using XENMEM_add_to_physmap with
> > XENMAPSPACE_shared_info.
> > 
> > Changes in v4:
> > 
> > - simpler parsing of Xen version in the compatible DT node.
> > 
> > Changes in v3:
> > 
> > - use the "xen,xen" notation rather than "arm,xen";
> > - add an additional check on the presence of the Xen version.
> > 
> > Changes in v2:
> > 
> > - replace pr_info with pr_debug.
> > 
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> > ---
> >  arch/arm/xen/enlighten.c |   61 ++++++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 61 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> > index c535540..6a0217d 100644
> > --- a/arch/arm/xen/enlighten.c
> > +++ b/arch/arm/xen/enlighten.c
> > @@ -5,6 +5,9 @@
> >  #include <asm/xen/hypervisor.h>
> >  #include <asm/xen/hypercall.h>
> >  #include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_address.h>
> >  
> >  struct start_info _xen_start_info;
> >  struct start_info *xen_start_info = &_xen_start_info;
> > @@ -33,3 +36,61 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> >  	return -ENOSYS;
> >  }
> >  EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> > +
> > +/*
> > + * see Documentation/devicetree/bindings/arm/xen.txt for the
> > + * documentation of the Xen Device Tree format.
> > + */
> > +static int __init xen_guest_init(void)
> > +{
> > +	struct xen_add_to_physmap xatp;
> > +	static struct shared_info *shared_info_page = 0;
> > +	struct device_node *node;
> > +	int len;
> > +	const char *s = NULL;
> > +	const char *version = NULL;
> > +	const char *xen_prefix = "xen,xen-";
> > +
> > +	node = of_find_compatible_node(NULL, NULL, "xen,xen");
> > +	if (!node) {
> > +		pr_debug("No Xen support\n");
> > +		return 0;
> > +	}
> > +	s = of_get_property(node, "compatible", &len);
> > +	if (strlen(xen_prefix) + 3  < len &&
> > +			!strncmp(xen_prefix, s, strlen(xen_prefix)))
> 
> If we have version '4.3.1' won't this trip us over?

This isn't an issue:

if (8 + 3 < 14 &&
    !strncmp("xen,xen-", "xen,xen-4.3.1", 8)

would return true

and version is set to "4.3.1".


> Or if we only have 'major' and 'minor', then won't '4.11' trip us
> over too?

For the same reason this shouldn't be an issue either:

if (8 + 3 < 13 &&
    !strncmp("xen,xen-", "xen,xen-4.11", 8)

would return true

and version would be set to "4.11".

BTW I have just tried both out of paranoia and it works as expected.


> > +		version = s + strlen(xen_prefix);
> > +	if (version == NULL) {
> > +		pr_debug("Xen version not found\n");
> > +		return 0;
> > +	}
> > +	xen_domain_type = XEN_HVM_DOMAIN;
> > +
> > +	if (!shared_info_page)
> > +		shared_info_page = (struct shared_info *)
> > +			get_zeroed_page(GFP_KERNEL);
> > +	if (!shared_info_page) {
> > +		pr_err("not enough memory\n");
> > +		return -ENOMEM;
> > +	}
> > +	xatp.domid = DOMID_SELF;
> > +	xatp.idx = 0;
> > +	xatp.space = XENMAPSPACE_shared_info;
> > +	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
> > +	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
> > +		BUG();
> > +
> > +	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
> > +
> > +	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
> > +	 * page, we use it in the event channel upcall and in some pvclock
> > +	 * related functions. We don't need the vcpu_info placement
> > +	 * optimizations because we don't use any pv_mmu or pv_irq op on
> > +	 * HVM.
> > +	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
> > +	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
> > +	 * for secondary CPUs as they are brought up. */
> > +	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
> > +	return 0;
> > +}
> > +core_initcall(xen_guest_init);
> > -- 
> > 1.7.2.5
>
diff mbox

Patch

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index c535540..6a0217d 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -5,6 +5,9 @@ 
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
 
 struct start_info _xen_start_info;
 struct start_info *xen_start_info = &_xen_start_info;
@@ -33,3 +36,61 @@  int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 	return -ENOSYS;
 }
 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
+
+/*
+ * see Documentation/devicetree/bindings/arm/xen.txt for the
+ * documentation of the Xen Device Tree format.
+ */
+static int __init xen_guest_init(void)
+{
+	struct xen_add_to_physmap xatp;
+	static struct shared_info *shared_info_page = 0;
+	struct device_node *node;
+	int len;
+	const char *s = NULL;
+	const char *version = NULL;
+	const char *xen_prefix = "xen,xen-";
+
+	node = of_find_compatible_node(NULL, NULL, "xen,xen");
+	if (!node) {
+		pr_debug("No Xen support\n");
+		return 0;
+	}
+	s = of_get_property(node, "compatible", &len);
+	if (strlen(xen_prefix) + 3  < len &&
+			!strncmp(xen_prefix, s, strlen(xen_prefix)))
+		version = s + strlen(xen_prefix);
+	if (version == NULL) {
+		pr_debug("Xen version not found\n");
+		return 0;
+	}
+	xen_domain_type = XEN_HVM_DOMAIN;
+
+	if (!shared_info_page)
+		shared_info_page = (struct shared_info *)
+			get_zeroed_page(GFP_KERNEL);
+	if (!shared_info_page) {
+		pr_err("not enough memory\n");
+		return -ENOMEM;
+	}
+	xatp.domid = DOMID_SELF;
+	xatp.idx = 0;
+	xatp.space = XENMAPSPACE_shared_info;
+	xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
+	if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+		BUG();
+
+	HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
+
+	/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
+	 * page, we use it in the event channel upcall and in some pvclock
+	 * related functions. We don't need the vcpu_info placement
+	 * optimizations because we don't use any pv_mmu or pv_irq op on
+	 * HVM.
+	 * The shared info contains exactly 1 CPU (the boot CPU). The guest
+	 * is required to use VCPUOP_register_vcpu_info to place vcpu info
+	 * for secondary CPUs as they are brought up. */
+	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
+	return 0;
+}
+core_initcall(xen_guest_init);