From 1cb71b69284ce002c299ea3a3dfa061cad78e7f7 Mon Sep 17 00:00:00 2001 From: Daniel De Graaf Date: Fri, 6 May 2011 15:13:22 -0400 Subject: [PATCH RFC 7/8] xen: Allow hardware domain != dom0 This adds a hypervisor command line option "hardware_dom=" which takes a domain ID. When the domain with this ID is created, it will be used as the hardware domain. This is intended to be used when domain 0 is a dedicated stub domain for domain building, allowing the hardware domain to be de-privileged and act only as a driver domain. Signed-off-by: Daniel De Graaf Acked-by: Keir Fraser Cc: Jan Beulich --- docs/misc/xen-command-line.markdown | 10 +++++++++ xen/arch/x86/domain_build.c | 4 +++- xen/common/domain.c | 5 +++++ xen/common/domctl.c | 41 +++++++++++++++++++++++++++++++++++++ xen/common/rangeset.c | 40 ++++++++++++++++++++++++++++++++++++ xen/include/xen/rangeset.h | 3 +++ xen/include/xen/sched.h | 10 +++++++-- xen/include/xsm/dummy.h | 6 ++++++ xen/include/xsm/xsm.h | 6 ++++++ xen/xsm/dummy.c | 2 ++ xen/xsm/flask/hooks.c | 6 ++++++ xen/xsm/flask/policy/access_vectors | 2 ++ 12 files changed, 132 insertions(+), 3 deletions(-) diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown index 87de2dc..6f5064f 100644 --- a/docs/misc/xen-command-line.markdown +++ b/docs/misc/xen-command-line.markdown @@ -590,6 +590,16 @@ Paging (HAP). Flag to enable 2 MB host page table support for Hardware Assisted Paging (HAP). +### hardware\_dom +> `= ` + +> Default: `0` + +Enable late hardware domain creation using the specified domain ID. This is +intended to be used when domain 0 is a stub domain which builds a disaggregated +system including a hardware domain with the specified domain ID. This option is +supported only when compiled with CONFIG\_XSM on x86. + ### hpetbroadcast > `= ` diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c index 08c40f8..1b61687 100644 --- a/xen/arch/x86/domain_build.c +++ b/xen/arch/x86/domain_build.c @@ -1150,7 +1150,9 @@ int __init construct_dom0( printk(" Xen warning: dom0 kernel broken ELF: %s\n", elf_check_broken(&elf)); - iommu_hwdom_init(hardware_domain); + if ( is_hardware_domain_by_id(d) ) + iommu_hwdom_init(d); + return 0; out: diff --git a/xen/common/domain.c b/xen/common/domain.c index 4036e69..2561236 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -61,6 +61,11 @@ struct domain *domain_list; struct domain *hardware_domain __read_mostly; +#ifdef CONFIG_LATE_HWDOM +domid_t hardware_domid __read_mostly; +integer_param("hardware_dom", hardware_domid); +#endif + struct vcpu *idle_vcpu[NR_CPUS] __read_mostly; vcpu_info_t dummy_vcpu_info; diff --git a/xen/common/domctl.c b/xen/common/domctl.c index af3614b..c77fe99 100644 --- a/xen/common/domctl.c +++ b/xen/common/domctl.c @@ -472,6 +472,47 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl) break; } +#ifdef CONFIG_LATE_HWDOM + if ( is_hardware_domain_by_id(d) ) + { + struct domain *dom0 = hardware_domain; + ASSERT(dom0->domain_id == 0); + + ret = xsm_init_hardware_domain(XSM_HOOK, d); + if ( ret ) + { + domain_kill(d); + d = NULL; + break; + } + + printk("Initialising hardware domain %d\n", hardware_domid); + hardware_domain = d; + + /* + * Hardware resource ranges for domain 0 have been set up from + * various sources intended to restrict the hardware domain's + * access. Apply these ranges to the actual hardware domain. + * + * Because the lists are being swapped, a side effect of this + * operation is that Domain 0's rangesets are cleared. Since + * domain 0 should not be accessing the hardware when it constructs + * a hardware domain, this should not be a problem. Both lists + * may be modified after this hypercall returns if a more complex + * device model is desired. + * + * Since late hardware domain initialization is only supported on + * x86, the reference to arch.ioport_caps does not need its own + * preprocessor conditional. + */ + rangeset_swap(d->irq_caps, dom0->irq_caps); + rangeset_swap(d->iomem_caps, dom0->iomem_caps); + rangeset_swap(d->arch.ioport_caps, dom0->arch.ioport_caps); + + iommu_hwdom_init(d); + } +#endif + ret = 0; memcpy(d->handle, op->u.createdomain.handle, diff --git a/xen/common/rangeset.c b/xen/common/rangeset.c index f09c0c4..52fae1f 100644 --- a/xen/common/rangeset.c +++ b/xen/common/rangeset.c @@ -438,3 +438,43 @@ void rangeset_domain_printk( spin_unlock(&d->rangesets_lock); } + +void rangeset_swap(struct rangeset *a, struct rangeset *b) +{ + struct list_head tmp; + if (&a < &b) + { + spin_lock(&a->lock); + spin_lock(&b->lock); + } + else + { + spin_lock(&b->lock); + spin_lock(&a->lock); + } + memcpy(&tmp, &a->range_list, sizeof(tmp)); + memcpy(&a->range_list, &b->range_list, sizeof(tmp)); + memcpy(&b->range_list, &tmp, sizeof(tmp)); + if ( a->range_list.next == &b->range_list ) + { + a->range_list.next = &a->range_list; + a->range_list.prev = &a->range_list; + } + else + { + a->range_list.next->prev = &a->range_list; + a->range_list.prev->next = &a->range_list; + } + if ( b->range_list.next == &a->range_list ) + { + b->range_list.next = &b->range_list; + b->range_list.prev = &b->range_list; + } + else + { + b->range_list.next->prev = &b->range_list; + b->range_list.prev->next = &b->range_list; + } + spin_unlock(&a->lock); + spin_unlock(&b->lock); +} diff --git a/xen/include/xen/rangeset.h b/xen/include/xen/rangeset.h index 1e16a6b..805ebde 100644 --- a/xen/include/xen/rangeset.h +++ b/xen/include/xen/rangeset.h @@ -73,4 +73,7 @@ void rangeset_printk( void rangeset_domain_printk( struct domain *d); +/* swap contents */ +void rangeset_swap(struct rangeset *a, struct rangeset *b); + #endif /* __XEN_RANGESET_H__ */ diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index 34447f1..50937db 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -46,6 +46,12 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t); /* A global pointer to the hardware domain (usually DOM0). */ extern struct domain *hardware_domain; +#ifdef CONFIG_LATE_HWDOM +extern domid_t hardware_domid; +#else +#define hardware_domid 0 +#endif + #ifndef CONFIG_COMPAT #define BITS_PER_EVTCHN_WORD(d) BITS_PER_XEN_ULONG #else @@ -795,7 +801,7 @@ void watchdog_domain_destroy(struct domain *d); * Use this check when the following are both true: * - Using this feature or interface requires full access to the hardware * (that is, this would not be suitable for a driver domain) - * - There is never a reason to deny dom0 access to this + * - There is never a reason to deny the hardware domain access to this */ #define is_hardware_domain(_d) ((_d) == hardware_domain) @@ -804,7 +810,7 @@ void watchdog_domain_destroy(struct domain *d); * hardware_domain variable. This is necessary inside domain_create where * hardware_domain is NULL and for some checks implementing CONFIG_LATE_HWDOM. */ -#define is_hardware_domain_by_id(_d) ((_d)->domain_id == 0) +#define is_hardware_domain_by_id(_d) ((_d)->domain_id == hardware_domid) /* This check is for functionality specific to a control domain */ #define is_control_domain(_d) ((_d)->is_privileged) diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h index e722155..8ca1117 100644 --- a/xen/include/xsm/dummy.h +++ b/xen/include/xsm/dummy.h @@ -299,6 +299,12 @@ static XSM_INLINE char *xsm_show_security_evtchn(struct domain *d, const struct return NULL; } +static XSM_INLINE int xsm_init_hardware_domain(XSM_DEFAULT_ARG struct domain *d) +{ + XSM_ASSERT_ACTION(XSM_HOOK); + return xsm_default_action(action, current->domain, d); +} + static XSM_INLINE int xsm_get_pod_target(XSM_DEFAULT_ARG struct domain *d) { XSM_ASSERT_ACTION(XSM_PRIV); diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h index 2cd3a3b..ef1c584 100644 --- a/xen/include/xsm/xsm.h +++ b/xen/include/xsm/xsm.h @@ -82,6 +82,7 @@ struct xsm_operations { int (*alloc_security_evtchn) (struct evtchn *chn); void (*free_security_evtchn) (struct evtchn *chn); char *(*show_security_evtchn) (struct domain *d, const struct evtchn *chn); + int (*init_hardware_domain) (struct domain *d); int (*get_pod_target) (struct domain *d); int (*set_pod_target) (struct domain *d); @@ -311,6 +312,11 @@ static inline char *xsm_show_security_evtchn (struct domain *d, const struct evt return xsm_ops->show_security_evtchn(d, chn); } +static inline int xsm_init_hardware_domain (xsm_default_t def, struct domain *d) +{ + return xsm_ops->init_hardware_domain(d); +} + static inline int xsm_get_pod_target (xsm_default_t def, struct domain *d) { return xsm_ops->get_pod_target(d); diff --git a/xen/xsm/dummy.c b/xen/xsm/dummy.c index b79e10f..c2804f2 100644 --- a/xen/xsm/dummy.c +++ b/xen/xsm/dummy.c @@ -58,6 +58,8 @@ void xsm_fixup_ops (struct xsm_operations *ops) set_to_dummy_if_null(ops, alloc_security_evtchn); set_to_dummy_if_null(ops, free_security_evtchn); set_to_dummy_if_null(ops, show_security_evtchn); + set_to_dummy_if_null(ops, init_hardware_domain); + set_to_dummy_if_null(ops, get_pod_target); set_to_dummy_if_null(ops, set_pod_target); diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c index 4ce31c9..f1a4a2d 100644 --- a/xen/xsm/flask/hooks.c +++ b/xen/xsm/flask/hooks.c @@ -327,6 +327,11 @@ static char *flask_show_security_evtchn(struct domain *d, const struct evtchn *c return ctx; } +static int flask_init_hardware_domain(struct domain *d) +{ + return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__CREATE_HARDWARE_DOMAIN); +} + static int flask_grant_mapref(struct domain *d1, struct domain *d2, uint32_t flags) { @@ -1500,6 +1505,7 @@ static struct xsm_operations flask_ops = { .alloc_security_evtchn = flask_alloc_security_evtchn, .free_security_evtchn = flask_free_security_evtchn, .show_security_evtchn = flask_show_security_evtchn, + .init_hardware_domain = flask_init_hardware_domain, .get_pod_target = flask_get_pod_target, .set_pod_target = flask_set_pod_target, diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors index a0ed13d..32371a9 100644 --- a/xen/xsm/flask/policy/access_vectors +++ b/xen/xsm/flask/policy/access_vectors @@ -198,6 +198,8 @@ class domain2 set_max_evtchn # XEN_DOMCTL_cacheflush cacheflush +# Creation of the hardware domain when it is not dom0 + create_hardware_domain } # Similar to class domain, but primarily contains domctls related to HVM domains -- 1.9.0