git: fe7d7ac40881 - main - hyperv: register intr handler as usermode-mapped if loaded as module

[Konstantin Belousov]

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=fe7d7ac40881c9d01a54bf57fff71a3af199f237

commit fe7d7ac40881c9d01a54bf57fff71a3af199f237
Author:     Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-01-12 16:35:58 +0000
Commit:     Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-06-05 15:03:18 +0000

    hyperv: register intr handler as usermode-mapped if loaded as module
    
    Normally raw interrupt handler is provided by the kernel text.  But
    vmbus module registers its own handler that needs to be mapped into
    userspace mapping on PTI kernels.
    
    Reported and reviewed by:       whu
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D30310
---
 sys/dev/hyperv/vmbus/vmbus.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sys/dev/hyperv/vmbus/vmbus.c b/sys/dev/hyperv/vmbus/vmbus.c
index d3568494405e..929eff33e7c9 100644
--- a/sys/dev/hyperv/vmbus/vmbus.c
+++ b/sys/dev/hyperv/vmbus/vmbus.c
@@ -45,6 +45,10 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/taskqueue.h>
 
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+
 #include <machine/bus.h>
 #include <machine/intr_machdep.h>
 #include <machine/metadata.h>
@@ -139,6 +143,7 @@ SYSCTL_INT(_hw_vmbus, OID_AUTO, pin_evttask, CTLFLAG_RDTUN,
     &vmbus_pin_evttask, 0, "Pin event tasks to their respective CPU");
 
 extern inthand_t IDTVEC(vmbus_isr), IDTVEC(vmbus_isr_pti);
+#define VMBUS_ISR_ADDR	trunc_page((uintptr_t)IDTVEC(vmbus_isr_pti))
 
 uint32_t			vmbus_current_version;
 
@@ -980,6 +985,10 @@ vmbus_intr_setup(struct vmbus_softc *sc)
 		    vmbus_msg_task, sc);
 	}
 
+#if defined(__amd64__) && defined(KLD_MODULE)
+	pmap_pti_add_kva(VMBUS_ISR_ADDR, VMBUS_ISR_ADDR + PAGE_SIZE, true);
+#endif
+
 	/*
 	 * All Hyper-V ISR required resources are setup, now let's find a
 	 * free IDT vector for Hyper-V ISR and set it up.
@@ -987,6 +996,9 @@ vmbus_intr_setup(struct vmbus_softc *sc)
 	sc->vmbus_idtvec = lapic_ipi_alloc(pti ? IDTVEC(vmbus_isr_pti) :
 	    IDTVEC(vmbus_isr));
 	if (sc->vmbus_idtvec < 0) {
+#if defined(__amd64__) && defined(KLD_MODULE)
+		pmap_pti_remove_kva(VMBUS_ISR_ADDR, VMBUS_ISR_ADDR + PAGE_SIZE);
+#endif
 		device_printf(sc->vmbus_dev, "cannot find free IDT vector\n");
 		return ENXIO;
 	}
@@ -1007,6 +1019,10 @@ vmbus_intr_teardown(struct vmbus_softc *sc)
 		sc->vmbus_idtvec = -1;
 	}
 
+#if defined(__amd64__) && defined(KLD_MODULE)
+	pmap_pti_remove_kva(VMBUS_ISR_ADDR, VMBUS_ISR_ADDR + PAGE_SIZE);
+#endif
+
 	CPU_FOREACH(cpu) {
 		if (VMBUS_PCPU_GET(sc, event_tq, cpu) != NULL) {
 			taskqueue_free(VMBUS_PCPU_GET(sc, event_tq, cpu));