[PATCH v4 10/11] KVM: x86/xen: Add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery
David Woodhouse
dwmw2 at infradead.org
Sat Nov 20 02:28:09 PST 2021
From: David Woodhouse <dwmw at amazon.co.uk>
This adds basic support for delivering 2 level event channels to a guest.
Initially, it only supports delivery via the IRQ routing table, triggered
by an eventfd. In order to do so, it has a kvm_xen_set_evtchn_fast()
function which will use the pre-mapped shared_info page if it already
exists and is still valid, while the slow path through the irqfd_inject
workqueue will remap the shared_info page if necessary.
It sets the bits in the shared_info page but not the vcpu_info; that is
deferred to __kvm_xen_has_interrupt() which raises the vector to the
appropriate vCPU.
Signed-off-by: David Woodhouse <dwmw at amazon.co.uk>
---
Documentation/virt/kvm/api.rst | 21 ++
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/irq_comm.c | 12 +
arch/x86/kvm/x86.c | 3 +-
arch/x86/kvm/xen.c | 262 +++++++++++++++++-
arch/x86/kvm/xen.h | 9 +
include/linux/kvm_host.h | 7 +
include/uapi/linux/kvm.h | 11 +
.../selftests/kvm/x86_64/xen_shinfo_test.c | 112 +++++++-
9 files changed, 431 insertions(+), 7 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 455664c39d42..ec4d693851a2 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -1799,6 +1799,7 @@ No flags are specified so far, the corresponding field must be set to zero.
struct kvm_irq_routing_msi msi;
struct kvm_irq_routing_s390_adapter adapter;
struct kvm_irq_routing_hv_sint hv_sint;
+ struct kvm_irq_routing_xen_evtchn xen_evtchn;
__u32 pad[8];
} u;
};
@@ -1808,6 +1809,7 @@ No flags are specified so far, the corresponding field must be set to zero.
#define KVM_IRQ_ROUTING_MSI 2
#define KVM_IRQ_ROUTING_S390_ADAPTER 3
#define KVM_IRQ_ROUTING_HV_SINT 4
+ #define KVM_IRQ_ROUTING_XEN_EVTCHN 5
flags:
@@ -1859,6 +1861,20 @@ address_hi must be zero.
__u32 sint;
};
+ struct kvm_irq_routing_xen_evtchn {
+ __u32 port;
+ __u32 vcpu;
+ __u32 priority;
+ };
+
+
+When KVM_CAP_XEN_HVM includes the KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL bit
+in its indication of supported features, routing to Xen event channels
+is supported. Although the priority field is present, only the value
+KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL is supported, which means delivery by
+2 level event channels. FIFO event channel support may be added in
+the future.
+
4.55 KVM_SET_TSC_KHZ
--------------------
@@ -7413,6 +7429,7 @@ PVHVM guests. Valid flags are::
#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 2)
+ #define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 3)
The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
ioctl is available, for the guest to set its hypercall page.
@@ -7432,6 +7449,10 @@ The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related
features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are
supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls.
+The KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL flag indicates that IRQ routing entries
+of the type KVM_IRQ_ROUTING_XEN_EVTCHN are supported, with the priority
+field set to indicate 2 level event channel delivery.
+
8.31 KVM_CAP_PPC_MULTITCE
-------------------------
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4b2b4ecf3b46..6ea2446ab851 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -604,6 +604,7 @@ struct kvm_vcpu_xen {
u64 last_steal;
u64 runstate_entry_time;
u64 runstate_times[4];
+ unsigned long evtchn_pending_sel;
};
struct kvm_vcpu_arch {
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index d5b72a08e566..afd2de84be60 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -24,6 +24,7 @@
#include "hyperv.h"
#include "x86.h"
+#include "xen.h"
static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
@@ -175,6 +176,13 @@ int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
return r;
break;
+#ifdef CONFIG_KVM_XEN
+ case KVM_IRQ_ROUTING_XEN_EVTCHN:
+ if (!level)
+ return -1;
+
+ return kvm_xen_set_evtchn_fast(e, kvm);
+#endif
default:
break;
}
@@ -310,6 +318,10 @@ int kvm_set_routing_entry(struct kvm *kvm,
e->hv_sint.vcpu = ue->u.hv_sint.vcpu;
e->hv_sint.sint = ue->u.hv_sint.sint;
break;
+#ifdef CONFIG_KVM_XEN
+ case KVM_IRQ_ROUTING_XEN_EVTCHN:
+ return kvm_xen_setup_evtchn(kvm, e, ue);
+#endif
default:
return -EINVAL;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5a403d92833f..fa56c590d8db 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4147,7 +4147,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_XEN_HVM:
r = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |
KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL |
- KVM_XEN_HVM_CONFIG_SHARED_INFO;
+ KVM_XEN_HVM_CONFIG_SHARED_INFO |
+ KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL;
if (sched_info_on())
r |= KVM_XEN_HVM_CONFIG_RUNSTATE;
break;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index da4bf2c6407f..4b380d2157a9 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -16,6 +16,7 @@
#include <trace/events/kvm.h>
#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>
+#include <xen/interface/event_channel.h>
#include "trace.h"
@@ -195,6 +196,8 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
{
+ unsigned long evtchn_pending_sel = READ_ONCE(v->arch.xen.evtchn_pending_sel);
+ bool atomic = in_atomic() || !task_is_running(current);
int err;
u8 rc = 0;
@@ -204,6 +207,9 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
*/
struct gfn_to_hva_cache *ghc = &v->arch.xen.vcpu_info_cache;
struct kvm_memslots *slots = kvm_memslots(v->kvm);
+ bool ghc_valid = slots->generation == ghc->generation &&
+ !kvm_is_error_hva(ghc->hva) && ghc->memslot;
+
unsigned int offset = offsetof(struct vcpu_info, evtchn_upcall_pending);
/* No need for compat handling here */
@@ -219,8 +225,7 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
* cache in kvm_read_guest_offset_cached(), but just uses
* __get_user() instead. And falls back to the slow path.
*/
- if (likely(slots->generation == ghc->generation &&
- !kvm_is_error_hva(ghc->hva) && ghc->memslot)) {
+ if (!evtchn_pending_sel && ghc_valid) {
/* Fast path */
pagefault_disable();
err = __get_user(rc, (u8 __user *)ghc->hva + offset);
@@ -239,11 +244,82 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
* and we'll end up getting called again from a context where we *can*
* fault in the page and wait for it.
*/
- if (in_atomic() || !task_is_running(current))
+ if (atomic)
return 1;
- kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset,
- sizeof(rc));
+ if (!ghc_valid) {
+ err = kvm_gfn_to_hva_cache_init(v->kvm, ghc, ghc->gpa, ghc->len);
+ if (err || !ghc->memslot) {
+ /*
+ * If this failed, userspace has screwed up the
+ * vcpu_info mapping. No interrupts for you.
+ */
+ return 0;
+ }
+ }
+
+ /*
+ * Now we have a valid (protected by srcu) userspace HVA in
+ * ghc->hva which points to the struct vcpu_info. If there
+ * are any bits in the in-kernel evtchn_pending_sel then
+ * we need to write those to the guest vcpu_info and set
+ * its evtchn_upcall_pending flag. If there aren't any bits
+ * to add, we only want to *check* evtchn_upcall_pending.
+ */
+ if (evtchn_pending_sel) {
+ bool long_mode = v->kvm->arch.xen.long_mode;
+
+ if (!user_access_begin((void *)ghc->hva, sizeof(struct vcpu_info)))
+ return 0;
+
+ if (IS_ENABLED(CONFIG_64BIT) && long_mode) {
+ struct vcpu_info __user *vi = (void *)ghc->hva;
+
+ /* Attempt to set the evtchn_pending_sel bits in the
+ * guest, and if that succeeds then clear the same
+ * bits in the in-kernel version. */
+ asm volatile("1:\t" LOCK_PREFIX "orq %0, %1\n"
+ "\tnotq %0\n"
+ "\t" LOCK_PREFIX "andq %0, %2\n"
+ "2:\n"
+ "\t.section .fixup,\"ax\"\n"
+ "3:\tjmp\t2b\n"
+ "\t.previous\n"
+ _ASM_EXTABLE_UA(1b, 3b)
+ : "=r" (evtchn_pending_sel),
+ "+m" (vi->evtchn_pending_sel),
+ "+m" (v->arch.xen.evtchn_pending_sel)
+ : "0" (evtchn_pending_sel));
+ } else {
+ struct compat_vcpu_info __user *vi = (void *)ghc->hva;
+ u32 evtchn_pending_sel32 = evtchn_pending_sel;
+
+ /* Attempt to set the evtchn_pending_sel bits in the
+ * guest, and if that succeeds then clear the same
+ * bits in the in-kernel version. */
+ asm volatile("1:\t" LOCK_PREFIX "orl %0, %1\n"
+ "\tnotl %0\n"
+ "\t" LOCK_PREFIX "andl %0, %2\n"
+ "2:\n"
+ "\t.section .fixup,\"ax\"\n"
+ "3:\tjmp\t2b\n"
+ "\t.previous\n"
+ _ASM_EXTABLE_UA(1b, 3b)
+ : "=r" (evtchn_pending_sel32),
+ "+m" (vi->evtchn_pending_sel),
+ "+m" (v->arch.xen.evtchn_pending_sel)
+ : "0" (evtchn_pending_sel32));
+ }
+ rc = 1;
+ unsafe_put_user(rc, (u8 __user *)ghc->hva + offset, err);
+
+ err:
+ user_access_end();
+
+ mark_page_dirty_in_slot(v->kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
+ } else {
+ __get_user(rc, (u8 __user *)ghc->hva + offset);
+ }
return rc;
}
@@ -740,3 +816,179 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
return 0;
}
+
+static inline int max_evtchn_port(struct kvm *kvm)
+{
+ if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode)
+ return EVTCHN_2L_NR_CHANNELS;
+ else
+ return COMPAT_EVTCHN_2L_NR_CHANNELS;
+}
+
+/*
+ * This follows the kvm_set_irq() API, so it returns:
+ * < 0 Interrupt was ignored (masked or not delivered for other reasons)
+ * = 0 Interrupt was coalesced (previous irq is still pending)
+ * > 0 Number of CPUs interrupt was delivered to
+ */
+int kvm_xen_set_evtchn_fast(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm)
+{
+ struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
+ struct kvm_vcpu *vcpu;
+ unsigned long *pending_bits, *mask_bits;
+ unsigned long flags;
+ int port_word_bit;
+ bool kick_vcpu = false;
+ int idx;
+ int rc;
+
+ vcpu = kvm_get_vcpu_by_id(kvm, e->xen_evtchn.vcpu);
+ if (!vcpu)
+ return -1;
+
+ if (!vcpu->arch.xen.vcpu_info_set)
+ return -1;
+
+ if (e->xen_evtchn.port >= max_evtchn_port(kvm))
+ return -1;
+
+ rc = -EWOULDBLOCK;
+ read_lock_irqsave(&gpc->lock, flags);
+
+ idx = srcu_read_lock(&kvm->srcu);
+ if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, PAGE_SIZE))
+ goto out_rcu;
+
+ if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) {
+ struct shared_info *shinfo = gpc->khva;
+ pending_bits = (unsigned long *)&shinfo->evtchn_pending;
+ mask_bits = (unsigned long *)&shinfo->evtchn_mask;
+ port_word_bit = e->xen_evtchn.port / 64;
+ } else {
+ struct compat_shared_info *shinfo = gpc->khva;
+ pending_bits = (unsigned long *)&shinfo->evtchn_pending;
+ mask_bits = (unsigned long *)&shinfo->evtchn_mask;
+ port_word_bit = e->xen_evtchn.port / 32;
+ }
+
+ /*
+ * If this port wasn't already set, and if it isn't masked, then
+ * we try to set the corresponding bit in the in-kernel shadow of
+ * evtchn_pending_sel for the target vCPU. And if *that* wasn't
+ * already set, then we kick the vCPU in question to write to the
+ * *real* evtchn_pending_sel in its own guest vcpu_info struct.
+ */
+ if (test_and_set_bit(e->xen_evtchn.port, pending_bits)) {
+ rc = 0; /* It was already raised */
+ } else if (test_bit(e->xen_evtchn.port, mask_bits)) {
+ rc = -1; /* Masked */
+ } else {
+ rc = 1; /* Delivered. But was the vCPU waking already? */
+ if (!test_and_set_bit(port_word_bit, &vcpu->arch.xen.evtchn_pending_sel))
+ kick_vcpu = true;
+ }
+
+ out_rcu:
+ srcu_read_unlock(&kvm->srcu, idx);
+ read_unlock_irqrestore(&gpc->lock, flags);
+
+ if (kick_vcpu) {
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+ kvm_vcpu_kick(vcpu);
+ }
+
+ return rc;
+}
+
+/* This is the version called from kvm_set_irq() as the .set function */
+static int evtchn_set_fn(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
+ int irq_source_id, int level, bool line_status)
+{
+ bool mm_borrowed = false;
+ int rc;
+
+ if (!level)
+ return -1;
+
+ rc = kvm_xen_set_evtchn_fast(e, kvm);
+ if (rc != -EWOULDBLOCK)
+ return rc;
+
+ if (current->mm != kvm->mm) {
+ /*
+ * If not on a thread which already belongs to this KVM,
+ * we'd better be in the irqfd workqueue.
+ */
+ if (WARN_ON_ONCE(current->mm))
+ return -EINVAL;
+
+ kthread_use_mm(kvm->mm);
+ mm_borrowed = true;
+ }
+
+ /*
+ * For the irqfd workqueue, using the main kvm->lock mutex is
+ * fine since this function is invoked from kvm_set_irq() with
+ * no other lock held, no srcu. In future if it will be called
+ * directly from a vCPU thread (e.g. on hypercall for an IPI)
+ * then it may need to switch to using a leaf-node mutex for
+ * serializing the shared_info mapping.
+ */
+ mutex_lock(&kvm->lock);
+
+ /*
+ * It is theoretically possible for the page to be unmapped
+ * and the MMU notifier to invalidate the shared_info before
+ * we even get to use it. In that case, this looks like an
+ * infinite loop. It was tempting to do it via the userspace
+ * HVA instead... but that just *hides* the fact that it's
+ * an infinite loop, because if a fault occurs and it waits
+ * for the page to come back, it can *still* immediately
+ * fault and have to wait again, repeatedly.
+ *
+ * Conversely, the page could also have been reinstated by
+ * another thread before we even obtain the mutex above, so
+ * check again *first* before remapping it.
+ */
+ do {
+ struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
+ int idx;
+
+ rc = kvm_xen_set_evtchn_fast(e, kvm);
+ if (rc != -EWOULDBLOCK)
+ break;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ rc = kvm_gfn_to_pfn_cache_refresh(kvm, gpc, gpc->gpa,
+ PAGE_SIZE, false);
+ srcu_read_unlock(&kvm->srcu, idx);
+ } while(!rc);
+
+ mutex_unlock(&kvm->lock);
+
+ if (mm_borrowed)
+ kthread_unuse_mm(kvm->mm);
+
+ return rc;
+}
+
+int kvm_xen_setup_evtchn(struct kvm *kvm,
+ struct kvm_kernel_irq_routing_entry *e,
+ const struct kvm_irq_routing_entry *ue)
+
+{
+ if (ue->u.xen_evtchn.port >= max_evtchn_port(kvm))
+ return -EINVAL;
+
+ /* We only support 2 level event channels for now */
+ if (ue->u.xen_evtchn.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL)
+ return -EINVAL;
+
+ e->xen_evtchn.port = ue->u.xen_evtchn.port;
+ e->xen_evtchn.vcpu = ue->u.xen_evtchn.vcpu;
+ e->xen_evtchn.priority = ue->u.xen_evtchn.priority;
+ e->set = evtchn_set_fn;
+
+ return 0;
+}
diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index cc0cf5f37450..adbcc9ed59db 100644
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -24,6 +24,12 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc);
void kvm_xen_init_vm(struct kvm *kvm);
void kvm_xen_destroy_vm(struct kvm *kvm);
+int kvm_xen_set_evtchn_fast(struct kvm_kernel_irq_routing_entry *e,
+ struct kvm *kvm);
+int kvm_xen_setup_evtchn(struct kvm *kvm,
+ struct kvm_kernel_irq_routing_entry *e,
+ const struct kvm_irq_routing_entry *ue);
+
static inline bool kvm_xen_msr_enabled(struct kvm *kvm)
{
return static_branch_unlikely(&kvm_xen_enabled.key) &&
@@ -134,6 +140,9 @@ struct compat_shared_info {
struct compat_arch_shared_info arch;
};
+#define COMPAT_EVTCHN_2L_NR_CHANNELS (8 * \
+ sizeof_field(struct compat_shared_info, \
+ evtchn_pending))
struct compat_vcpu_runstate_info {
int state;
uint64_t state_entry_time;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 457c38d75913..47fbc253d72b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -470,6 +470,12 @@ struct kvm_hv_sint {
u32 sint;
};
+struct kvm_xen_evtchn {
+ u32 port;
+ u32 vcpu;
+ u32 priority;
+};
+
struct kvm_kernel_irq_routing_entry {
u32 gsi;
u32 type;
@@ -490,6 +496,7 @@ struct kvm_kernel_irq_routing_entry {
} msi;
struct kvm_s390_adapter_int adapter;
struct kvm_hv_sint hv_sint;
+ struct kvm_xen_evtchn xen_evtchn;
};
struct hlist_node link;
};
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 1daa45268de2..12421e76adcb 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1162,11 +1162,20 @@ struct kvm_irq_routing_hv_sint {
__u32 sint;
};
+struct kvm_irq_routing_xen_evtchn {
+ __u32 port;
+ __u32 vcpu;
+ __u32 priority;
+};
+
+#define KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL ((__u32)(-1))
+
/* gsi routing entry types */
#define KVM_IRQ_ROUTING_IRQCHIP 1
#define KVM_IRQ_ROUTING_MSI 2
#define KVM_IRQ_ROUTING_S390_ADAPTER 3
#define KVM_IRQ_ROUTING_HV_SINT 4
+#define KVM_IRQ_ROUTING_XEN_EVTCHN 5
struct kvm_irq_routing_entry {
__u32 gsi;
@@ -1178,6 +1187,7 @@ struct kvm_irq_routing_entry {
struct kvm_irq_routing_msi msi;
struct kvm_irq_routing_s390_adapter adapter;
struct kvm_irq_routing_hv_sint hv_sint;
+ struct kvm_irq_routing_xen_evtchn xen_evtchn;
__u32 pad[8];
} u;
};
@@ -1208,6 +1218,7 @@ struct kvm_x86_mce {
#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1)
#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2)
#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 3)
+#define KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL (1 << 4)
struct kvm_xen_hvm_config {
__u32 flags;
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index a0699f00b3d6..a865e60a042c 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -14,6 +14,9 @@
#include <stdint.h>
#include <time.h>
#include <sched.h>
+#include <signal.h>
+
+#include <sys/eventfd.h>
#define VCPU_ID 5
@@ -22,10 +25,12 @@
#define SHINFO_REGION_SLOT 10
#define PAGE_SIZE 4096
+#define SHINFO_ADDR (SHINFO_REGION_GPA)
#define PVTIME_ADDR (SHINFO_REGION_GPA + PAGE_SIZE)
#define RUNSTATE_ADDR (SHINFO_REGION_GPA + PAGE_SIZE + 0x20)
#define VCPU_INFO_ADDR (SHINFO_REGION_GPA + 0x40)
+#define SHINFO_VADDR (SHINFO_REGION_GVA)
#define RUNSTATE_VADDR (SHINFO_REGION_GVA + PAGE_SIZE + 0x20)
#define VCPU_INFO_VADDR (SHINFO_REGION_GVA + 0x40)
@@ -73,15 +78,30 @@ struct vcpu_info {
struct pvclock_vcpu_time_info time;
}; /* 64 bytes (x86) */
+struct shared_info {
+ struct vcpu_info vcpu_info[32];
+ unsigned long evtchn_pending[64];
+ unsigned long evtchn_mask[64];
+ struct pvclock_wall_clock wc;
+ uint32_t wc_sec_hi;
+ /* arch_shared_info here */
+};
+
#define RUNSTATE_running 0
#define RUNSTATE_runnable 1
#define RUNSTATE_blocked 2
#define RUNSTATE_offline 3
+struct {
+ struct kvm_irq_routing info;
+ struct kvm_irq_routing_entry entries[2];
+} irq_routes;
+
static void evtchn_handler(struct ex_regs *regs)
{
struct vcpu_info *vi = (void *)VCPU_INFO_VADDR;
vi->evtchn_upcall_pending = 0;
+ vi->evtchn_pending_sel = 0;
GUEST_SYNC(0x20);
}
@@ -127,7 +147,19 @@ static void guest_code(void)
GUEST_SYNC(6);
GUEST_ASSERT(rs->time[RUNSTATE_runnable] >= MIN_STEAL_TIME);
- GUEST_DONE();
+ /* Attempt to deliver a *masked* interrupt */
+ GUEST_SYNC(7);
+
+ /* Wait until we see the bit set */
+ struct shared_info *si = (void *)SHINFO_VADDR;
+ while (!si->evtchn_pending[0])
+ __asm__ __volatile__ ("rep nop" : : : "memory");
+
+ /* Now deliver an *unmasked* interrupt */
+ GUEST_SYNC(8);
+
+ for (;;)
+ __asm__ __volatile__ ("rep nop" : : : "memory");
}
static int cmp_timespec(struct timespec *a, struct timespec *b)
@@ -144,6 +176,11 @@ static int cmp_timespec(struct timespec *a, struct timespec *b)
return 0;
}
+static void handle_alrm(int sig)
+{
+ TEST_FAIL("IRQ delivery timed out");
+}
+
int main(int argc, char *argv[])
{
struct timespec min_ts, max_ts, vm_ts;
@@ -155,6 +192,7 @@ int main(int argc, char *argv[])
}
bool do_runstate_tests = !!(xen_caps & KVM_XEN_HVM_CONFIG_RUNSTATE);
+ bool do_eventfd_tests = !!(xen_caps & KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL);
clock_gettime(CLOCK_REALTIME, &min_ts);
@@ -166,6 +204,11 @@ int main(int argc, char *argv[])
SHINFO_REGION_GPA, SHINFO_REGION_SLOT, 2, 0);
virt_map(vm, SHINFO_REGION_GVA, SHINFO_REGION_GPA, 2);
+ struct shared_info *shinfo = addr_gpa2hva(vm, SHINFO_VADDR);
+
+ int zero_fd = open("/dev/zero", O_RDONLY);
+ TEST_ASSERT(zero_fd != -1, "Failed to open /dev/zero");
+
struct kvm_xen_hvm_config hvmc = {
.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
.msr = XEN_HYPERCALL_MSR,
@@ -184,6 +227,16 @@ int main(int argc, char *argv[])
};
vm_ioctl(vm, KVM_XEN_HVM_SET_ATTR, &ha);
+ /*
+ * Test what happens when the HVA of the shinfo page is remapped after
+ * the kernel has a reference to it. But make sure we copy the clock
+ * info over since that's only set at setup time, and we test it later.
+ */
+ struct pvclock_wall_clock wc_copy = shinfo->wc;
+ void *m = mmap(shinfo, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_FIXED|MAP_PRIVATE, zero_fd, 0);
+ TEST_ASSERT(m == shinfo, "Failed to map /dev/zero over shared info");
+ shinfo->wc = wc_copy;
+
struct kvm_xen_vcpu_attr vi = {
.type = KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO,
.u.gpa = VCPU_INFO_ADDR,
@@ -214,6 +267,49 @@ int main(int argc, char *argv[])
vcpu_ioctl(vm, VCPU_ID, KVM_XEN_VCPU_SET_ATTR, &st);
}
+ int irq_fd[2] = { -1, -1 };
+
+ if (do_eventfd_tests) {
+ irq_fd[0] = eventfd(0, 0);
+ irq_fd[1] = eventfd(0, 0);
+
+ /* Unexpected, but not a KVM failure */
+ if (irq_fd[0] == -1 || irq_fd[1] == -1)
+ do_eventfd_tests = false;
+ }
+
+ if (do_eventfd_tests) {
+ irq_routes.info.nr = 2;
+
+ irq_routes.entries[0].gsi = 32;
+ irq_routes.entries[0].type = KVM_IRQ_ROUTING_XEN_EVTCHN;
+ irq_routes.entries[0].u.xen_evtchn.port = 15;
+ irq_routes.entries[0].u.xen_evtchn.vcpu = VCPU_ID;
+ irq_routes.entries[0].u.xen_evtchn.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
+
+ irq_routes.entries[1].gsi = 33;
+ irq_routes.entries[1].type = KVM_IRQ_ROUTING_XEN_EVTCHN;
+ irq_routes.entries[1].u.xen_evtchn.port = 66;
+ irq_routes.entries[1].u.xen_evtchn.vcpu = VCPU_ID;
+ irq_routes.entries[1].u.xen_evtchn.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL;
+
+ vm_ioctl(vm, KVM_SET_GSI_ROUTING, &irq_routes);
+
+ struct kvm_irqfd ifd = { };
+
+ ifd.fd = irq_fd[0];
+ ifd.gsi = 32;
+ vm_ioctl(vm, KVM_IRQFD, &ifd);
+
+ ifd.fd = irq_fd[1];
+ ifd.gsi = 33;
+ vm_ioctl(vm, KVM_IRQFD, &ifd);
+
+ struct sigaction sa = { };
+ sa.sa_handler = handle_alrm;
+ sigaction(SIGALRM, &sa, NULL);
+ }
+
struct vcpu_info *vinfo = addr_gpa2hva(vm, VCPU_INFO_VADDR);
vinfo->evtchn_upcall_pending = 0;
@@ -289,9 +385,23 @@ int main(int argc, char *argv[])
sched_yield();
} while (get_run_delay() < rundelay);
break;
+ case 7:
+ if (!do_eventfd_tests)
+ goto done;
+ shinfo->evtchn_mask[0] = 0x8000;
+ eventfd_write(irq_fd[0], 1UL);
+ alarm(1);
+ break;
+ case 8:
+ eventfd_write(irq_fd[1], 1UL);
+ evtchn_irq_expected = true;
+ break;
+
case 0x20:
TEST_ASSERT(evtchn_irq_expected, "Unexpected event channel IRQ");
evtchn_irq_expected = false;
+ if (shinfo->evtchn_pending[1])
+ goto done;
break;
}
break;
--
2.31.1
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