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authorJane Malalane <jane.malalane@citrix.com>2022-07-29 08:04:16 +0100
committerJuergen Gross <jgross@suse.com>2022-08-12 11:28:21 +0200
commitb1c3497e604ddccea5af4071831ed0e4680fb35e (patch)
tree108b8bd765f1e0496592013bb988ac329ca19de9 /drivers
parent251e90e7e346a23742b90e2c4db19d322e071d99 (diff)
x86/xen: Add support for HVMOP_set_evtchn_upcall_vector
Implement support for the HVMOP_set_evtchn_upcall_vector hypercall in order to set the per-vCPU event channel vector callback on Linux and use it in preference of HVM_PARAM_CALLBACK_IRQ. If the per-VCPU vector setup is successful on BSP, use this method for the APs. If not, fallback to the global vector-type callback. Also register callback_irq at per-vCPU event channel setup to trick toolstack to think the domain is enlightened. Suggested-by: "Roger Pau Monné" <roger.pau@citrix.com> Signed-off-by: Jane Malalane <jane.malalane@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20220729070416.23306-1-jane.malalane@citrix.com Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/xen/events/events_base.c53
1 files changed, 47 insertions, 6 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 46d9295d9a6e..206d4b466e44 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -45,6 +45,7 @@
#include <asm/irq.h>
#include <asm/io_apic.h>
#include <asm/i8259.h>
+#include <asm/xen/cpuid.h>
#include <asm/xen/pci.h>
#endif
#include <asm/sync_bitops.h>
@@ -2183,6 +2184,7 @@ static struct irq_chip xen_percpu_chip __read_mostly = {
.irq_ack = ack_dynirq,
};
+#ifdef CONFIG_X86
#ifdef CONFIG_XEN_PVHVM
/* Vector callbacks are better than PCI interrupts to receive event
* channel notifications because we can receive vector callbacks on any
@@ -2195,11 +2197,48 @@ void xen_setup_callback_vector(void)
callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
if (xen_set_callback_via(callback_via)) {
pr_err("Request for Xen HVM callback vector failed\n");
- xen_have_vector_callback = 0;
+ xen_have_vector_callback = false;
}
}
}
+/*
+ * Setup per-vCPU vector-type callbacks. If this setup is unavailable,
+ * fallback to the global vector-type callback.
+ */
+static __init void xen_init_setup_upcall_vector(void)
+{
+ if (!xen_have_vector_callback)
+ return;
+
+ if ((cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) &&
+ !xen_set_upcall_vector(0))
+ xen_percpu_upcall = true;
+ else if (xen_feature(XENFEAT_hvm_callback_vector))
+ xen_setup_callback_vector();
+ else
+ xen_have_vector_callback = false;
+}
+
+int xen_set_upcall_vector(unsigned int cpu)
+{
+ int rc;
+ xen_hvm_evtchn_upcall_vector_t op = {
+ .vector = HYPERVISOR_CALLBACK_VECTOR,
+ .vcpu = per_cpu(xen_vcpu_id, cpu),
+ };
+
+ rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &op);
+ if (rc)
+ return rc;
+
+ /* Trick toolstack to think we are enlightened. */
+ if (!cpu)
+ rc = xen_set_callback_via(1);
+
+ return rc;
+}
+
static __init void xen_alloc_callback_vector(void)
{
if (!xen_have_vector_callback)
@@ -2210,8 +2249,11 @@ static __init void xen_alloc_callback_vector(void)
}
#else
void xen_setup_callback_vector(void) {}
+static inline void xen_init_setup_upcall_vector(void) {}
+int xen_set_upcall_vector(unsigned int cpu) {}
static inline void xen_alloc_callback_vector(void) {}
-#endif
+#endif /* CONFIG_XEN_PVHVM */
+#endif /* CONFIG_X86 */
bool xen_fifo_events = true;
module_param_named(fifo_events, xen_fifo_events, bool, 0);
@@ -2271,10 +2313,9 @@ void __init xen_init_IRQ(void)
if (xen_initial_domain())
pci_xen_initial_domain();
}
- if (xen_feature(XENFEAT_hvm_callback_vector)) {
- xen_setup_callback_vector();
- xen_alloc_callback_vector();
- }
+ xen_init_setup_upcall_vector();
+ xen_alloc_callback_vector();
+
if (xen_hvm_domain()) {
native_init_IRQ();

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