Fix a bug in the passthru implementation where it would assume that all

devices are MSI-X capable. This in turn would lead it to treat bar 0 as
the MSI-X table bar even if the underlying device did not support MSI-X.

Fix this by providing an API to query the MSI-X table index of the emulated
device. If the underlying device does not support MSI-X then this API will
return -1.

Obtained from:	NetApp

4 files changed, 34 insertions, 8 deletions

diff --git a/usr.sbin/bhyve/pci_emul.c b/usr.sbin/bhyve/pci_emul.c
index d6315cf..32a3deb 100644
--- a/usr.sbin/bhyve/pci_emul.c
+++ b/usr.sbin/bhyve/pci_emul.c
@@ -254,6 +254,26 @@ pci_emul_msix_tread(struct pci_devinst *pi, uint64_t offset, int size)
 	return (retval);
 }
 
+int
+pci_msix_table_bar(struct pci_devinst *pi)
+{
+
+	if (pi->pi_msix.table != NULL)
+		return (pi->pi_msix.table_bar);
+	else
+		return (-1);
+}
+
+int
+pci_msix_pba_bar(struct pci_devinst *pi)
+{
+
+	if (pi->pi_msix.table != NULL)
+		return (pi->pi_msix.pba_bar);
+	else
+		return (-1);
+}
+
 static int
 pci_emul_io_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
 		    uint32_t *eax, void *arg)
diff --git a/usr.sbin/bhyve/pci_emul.h b/usr.sbin/bhyve/pci_emul.h
index 5338aec..8c6260c 100644
--- a/usr.sbin/bhyve/pci_emul.h
+++ b/usr.sbin/bhyve/pci_emul.h
@@ -169,6 +169,8 @@ void	pci_lintr_deassert(struct pci_devinst *pi);
 int	pci_lintr_request(struct pci_devinst *pi, int ivec);
 int	pci_msi_enabled(struct pci_devinst *pi);
 int	pci_msix_enabled(struct pci_devinst *pi);
+int	pci_msix_table_bar(struct pci_devinst *pi);
+int	pci_msix_pba_bar(struct pci_devinst *pi);
 int	pci_msi_msgnum(struct pci_devinst *pi);
 void	pci_parse_slot(char *opt, int legacy);
 void	pci_populate_msicap(struct msicap *cap, int msgs, int nextptr);
diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
index 26cf4d1..131f08a 100644
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -361,6 +361,8 @@ init_msix_table(struct vmctx *ctx, struct passthru_softc *sc, uint64_t base)
 	size_t len;
 	struct pci_devinst *pi = sc->psc_pi;
 
+	assert(pci_msix_table_bar(pi) >= 0 && pci_msix_pba_bar(pi) >= 0);
+
 	/* 
 	 * If the MSI-X table BAR maps memory intended for
 	 * other uses, it is at least assured that the table 
@@ -370,7 +372,9 @@ init_msix_table(struct vmctx *ctx, struct passthru_softc *sc, uint64_t base)
 	if (pi->pi_msix.pba_bar == pi->pi_msix.table_bar && 
 	    ((pi->pi_msix.pba_offset - pi->pi_msix.table_offset) < 4096)) {
 		/* Need to also emulate the PBA, not supported yet */
-		printf("Unsupported MSI-X table and PBA in same page\n");
+		printf("Unsupported MSI-X configuration: %d/%d/%d\n",
+		       sc->psc_sel.pc_bus, sc->psc_sel.pc_dev,
+		       sc->psc_sel.pc_func);
 		return (-1);
 	}
 
@@ -447,7 +451,7 @@ cfginitbar(struct vmctx *ctx, struct passthru_softc *sc)
 			return (-1);
 
 		/* The MSI-X table needs special handling */
-		if (i == pi->pi_msix.table_bar) {
+		if (i == pci_msix_table_bar(pi)) {
 			error = init_msix_table(ctx, sc, base);
 			if (error) 
 				return (-1);
@@ -688,7 +692,7 @@ passthru_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, int baridx,
 
 	sc = pi->pi_arg;
 
-	if (pi->pi_msix.table_bar == baridx) {
+	if (baridx == pci_msix_table_bar(pi)) {
 		msix_table_write(ctx, vcpu, sc, offset, size, value);
 	} else {
 		assert(pi->pi_bar[baridx].type == PCIBAR_IO);
@@ -712,7 +716,7 @@ passthru_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi, int baridx,
 
 	sc = pi->pi_arg;
 
-	if (pi->pi_msix.table_bar == baridx) {
+	if (baridx == pci_msix_table_bar(pi)) {
 		val = msix_table_read(sc, offset, size);
 	} else {
 		assert(pi->pi_bar[baridx].type == PCIBAR_IO);
diff --git a/usr.sbin/bhyve/pci_virtio_net.c b/usr.sbin/bhyve/pci_virtio_net.c
index 444e0e5..327ebf7 100644
--- a/usr.sbin/bhyve/pci_virtio_net.c
+++ b/usr.sbin/bhyve/pci_virtio_net.c
@@ -685,8 +685,8 @@ pci_vtnet_write(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
 	void *ptr;
 
 	if (use_msix) {
-		if (baridx == pi->pi_msix.table_bar ||
-		    baridx == pi->pi_msix.pba_bar) {
+		if (baridx == pci_msix_table_bar(pi) ||
+		    baridx == pci_msix_pba_bar(pi)) {
 			pci_emul_msix_twrite(pi, offset, size, value);
 			return;
 		}
@@ -781,8 +781,8 @@ pci_vtnet_read(struct vmctx *ctx, int vcpu, struct pci_devinst *pi,
 	uint64_t value;
 
 	if (use_msix) {
-		if (baridx == pi->pi_msix.table_bar ||
-		    baridx == pi->pi_msix.pba_bar) {
+		if (baridx == pci_msix_table_bar(pi) ||
+		    baridx == pci_msix_pba_bar(pi)) {
 			return (pci_emul_msix_tread(pi, offset, size));
 		}
 	}