MFC r302460: Add emulation for multiple (up to 16) MSI vectors for AHCI.

It was useless before, but may improve performance now if multiple devices
are configured and guest supports this feature.

Sponsored by:   iXsystems, Inc.

2 files changed, 99 insertions, 41 deletions

diff --git a/usr.sbin/bhyve/pci_ahci.c b/usr.sbin/bhyve/pci_ahci.c
index 2b20e27..1cc9594 100644
--- a/usr.sbin/bhyve/pci_ahci.c
+++ b/usr.sbin/bhyve/pci_ahci.c
@@ -135,6 +135,7 @@ struct ahci_port {
 	uint8_t *cmd_lst;
 	uint8_t *rfis;
 	char ident[20 + 1];
+	int port;
 	int atapi;
 	int reset;
 	int waitforclear;
@@ -219,47 +220,95 @@ static inline void lba_to_msf(uint8_t *buf, int lba)
 }
 
 /*
- * generate HBA intr depending on whether or not ports within
- * the controller have an interrupt pending.
+ * Generate HBA interrupts on global IS register write.
  */
 static void
-ahci_generate_intr(struct pci_ahci_softc *sc)
+ahci_generate_intr(struct pci_ahci_softc *sc, uint32_t mask)
 {
-	struct pci_devinst *pi;
-	int i;
-
-	pi = sc->asc_pi;
+	struct pci_devinst *pi = sc->asc_pi;
+	struct ahci_port *p;
+	int i, nmsg;
+	uint32_t mmask;
 
+	/* Update global IS from PxIS/PxIE. */
 	for (i = 0; i < sc->ports; i++) {
-		struct ahci_port *pr;
-		pr = &sc->port[i];
-		if (pr->is & pr->ie)
+		p = &sc->port[i];
+		if (p->is & p->ie)
 			sc->is |= (1 << i);
 	}
+	DPRINTF("%s(%08x) %08x\n", __func__, mask, sc->is);
+
+	/* If there is nothing enabled -- clear legacy interrupt and exit. */
+	if (sc->is == 0 || (sc->ghc & AHCI_GHC_IE) == 0) {
+		if (sc->lintr) {
+			pci_lintr_deassert(pi);
+			sc->lintr = 0;
+		}
+		return;
+	}
 
-	DPRINTF("%s %x\n", __func__, sc->is);
-
-	if (sc->is && (sc->ghc & AHCI_GHC_IE)) {		
-		if (pci_msi_enabled(pi)) {
-			/*
-			 * Generate an MSI interrupt on every edge
-			 */
-			pci_generate_msi(pi, 0);
-		} else if (!sc->lintr) {
-			/*
-			 * Only generate a pin-based interrupt if one wasn't
-			 * in progress
-			 */
+	/* If there is anything and no MSI -- assert legacy interrupt. */
+	nmsg = pci_msi_maxmsgnum(pi);
+	if (nmsg == 0) {
+		if (!sc->lintr) {
 			sc->lintr = 1;
 			pci_lintr_assert(pi);
 		}
-	} else if (sc->lintr) {
-		/*
-		 * No interrupts: deassert pin-based signal if it had
-		 * been asserted
-		 */
-		pci_lintr_deassert(pi);
-		sc->lintr = 0;
+		return;
+	}
+
+	/* Assert respective MSIs for ports that were touched. */
+	for (i = 0; i < nmsg; i++) {
+		if (sc->ports <= nmsg || i < nmsg - 1)
+			mmask = 1 << i;
+		else
+			mmask = 0xffffffff << i;
+		if (sc->is & mask && mmask & mask)
+			pci_generate_msi(pi, i);
+	}
+}
+
+/*
+ * Generate HBA interrupt on specific port event.
+ */
+static void
+ahci_port_intr(struct ahci_port *p)
+{
+	struct pci_ahci_softc *sc = p->pr_sc;
+	struct pci_devinst *pi = sc->asc_pi;
+	int nmsg;
+
+	DPRINTF("%s(%d) %08x/%08x %08x\n", __func__,
+	    p->port, p->is, p->ie, sc->is);
+
+	/* If there is nothing enabled -- we are done. */
+	if ((p->is & p->ie) == 0)
+		return;
+
+	/* In case of non-shared MSI always generate interrupt. */
+	nmsg = pci_msi_maxmsgnum(pi);
+	if (sc->ports <= nmsg || p->port < nmsg - 1) {
+		sc->is |= (1 << p->port);
+		if ((sc->ghc & AHCI_GHC_IE) == 0)
+			return;
+		pci_generate_msi(pi, p->port);
+		return;
+	}
+
+	/* If IS for this port is already set -- do nothing. */
+	if (sc->is & (1 << p->port))
+		return;
+
+	sc->is |= (1 << p->port);
+
+	/* If interrupts are enabled -- generate one. */
+	if ((sc->ghc & AHCI_GHC_IE) == 0)
+		return;
+	if (nmsg > 0) {
+		pci_generate_msi(pi, nmsg - 1);
+	} else if (!sc->lintr) {
+		sc->lintr = 1;
+		pci_lintr_assert(pi);
 	}
 }
 
@@ -297,8 +346,10 @@ ahci_write_fis(struct ahci_port *p, enum sata_fis_type ft, uint8_t *fis)
 	}
 	memcpy(p->rfis + offset, fis, len);
 	if (irq) {
-		p->is |= irq;
-		ahci_generate_intr(p->pr_sc);
+		if (~p->is & irq) {
+			p->is |= irq;
+			ahci_port_intr(p);
+		}
 	}
 }
 
@@ -1740,7 +1791,7 @@ ahci_handle_slot(struct ahci_port *p, int slot)
 	struct pci_ahci_softc *sc;
 	uint8_t *cfis;
 #ifdef AHCI_DEBUG
-	int cfl;
+	int cfl, i;
 #endif
 
 	sc = p->pr_sc;
@@ -2001,10 +2052,11 @@ pci_ahci_port_write(struct pci_ahci_softc *sc, uint64_t offset, uint64_t value)
 		break;
 	case AHCI_P_IS:
 		p->is &= ~value;
+		ahci_port_intr(p);
 		break;
 	case AHCI_P_IE:
 		p->ie = value & 0xFDC000FF;
-		ahci_generate_intr(sc);
+		ahci_port_intr(p);
 		break;
 	case AHCI_P_CMD:
 	{
@@ -2094,16 +2146,19 @@ pci_ahci_host_write(struct pci_ahci_softc *sc, uint64_t offset, uint64_t value)
 		DPRINTF("pci_ahci_host: read only registers 0x%"PRIx64"\n", offset);
 		break;
 	case AHCI_GHC:
-		if (value & AHCI_GHC_HR)
+		if (value & AHCI_GHC_HR) {
 			ahci_reset(sc);
-		else if (value & AHCI_GHC_IE) {
-			sc->ghc |= AHCI_GHC_IE;
-			ahci_generate_intr(sc);
+			break;
 		}
+		if (value & AHCI_GHC_IE)
+			sc->ghc |= AHCI_GHC_IE;
+		else
+			sc->ghc &= ~AHCI_GHC_IE;
+		ahci_generate_intr(sc, 0xffffffff);
 		break;
 	case AHCI_IS:
 		sc->is &= ~value;
-		ahci_generate_intr(sc);
+		ahci_generate_intr(sc, value);
 		break;
 	default:
 		break;
@@ -2297,6 +2352,7 @@ pci_ahci_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts, int atapi)
 		}	
 		sc->port[p].bctx = bctxt;
 		sc->port[p].pr_sc = sc;
+		sc->port[p].port = p;
 		sc->port[p].atapi = atapi;
 
 		/*
@@ -2341,7 +2397,9 @@ pci_ahci_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts, int atapi)
 	pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_STORAGE);
 	pci_set_cfgdata8(pi, PCIR_SUBCLASS, PCIS_STORAGE_SATA);
 	pci_set_cfgdata8(pi, PCIR_PROGIF, PCIP_STORAGE_SATA_AHCI_1_0);
-	pci_emul_add_msicap(pi, 1);
+	p = MIN(sc->ports, 16);
+	p = flsl(p) - ((p & (p - 1)) ? 0 : 1);
+	pci_emul_add_msicap(pi, 1 << p);
 	pci_emul_alloc_bar(pi, 5, PCIBAR_MEM32,
 	    AHCI_OFFSET + sc->ports * AHCI_STEP);
 
diff --git a/usr.sbin/bhyve/pci_emul.h b/usr.sbin/bhyve/pci_emul.h
index d74950b..0fffb19 100644
--- a/usr.sbin/bhyve/pci_emul.h
+++ b/usr.sbin/bhyve/pci_emul.h
@@ -230,7 +230,7 @@ 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);
+int	pci_msi_maxmsgnum(struct pci_devinst *pi);
 int	pci_parse_slot(char *opt);
 void	pci_populate_msicap(struct msicap *cap, int msgs, int nextptr);
 int	pci_emul_add_msixcap(struct pci_devinst *pi, int msgnum, int barnum);