From 082751e82bed9482fc75863e0b305949bb230c6a Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 15 Mar 2016 19:34:34 +0100 Subject: ivshmem: Clean up MSI-X conditions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are three predicates related to MSI-X: * ivshmem_has_feature(s, IVSHMEM_MSI) is true unless the non-MSI-X variant of the device is selected with msi=off. * msix_present() is true when the device has the PCI capability MSI-X. It's initially false, and becomes true during successful realize of the MSI-X variant of the device. Thus, it's the same as ivshmem_has_feature(s, IVSHMEM_MSI) for realized devices. * msix_enabled() is true when msix_present() is true and guest software has enabled MSI-X. Code that differs between the non-MSI-X and the MSI-X variant of the device needs to be guarded by ivshmem_has_feature(s, IVSHMEM_MSI) or by msix_present(), except the latter works only for realized devices. Code that depends on whether MSI-X is in use needs to be guarded with msix_enabled(). Code review led me to two minor messes: * ivshmem_vector_notify() calls msix_notify() even when !msix_enabled(), unlike most other MSI-X-capable devices. As far as I can tell, msix_notify() does nothing when !msix_enabled(). Add the guard anyway. * Most callers of ivshmem_use_msix() guard it with ivshmem_has_feature(s, IVSHMEM_MSI). Not necessary, because ivshmem_use_msix() does nothing when !msix_present(). That's ivshmem's only use of msix_present(), though. Guard it consistently, and drop the now redundant msix_present() check. While there, rename ivshmem_use_msix() to ivshmem_msix_vector_use(). Signed-off-by: Markus Armbruster Message-Id: <1458066895-20632-20-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau --- hw/misc/ivshmem.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) (limited to 'hw') diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 1debce3..abcb1c1 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -274,7 +274,9 @@ static void ivshmem_vector_notify(void *opaque) IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector); if (ivshmem_has_feature(s, IVSHMEM_MSI)) { - msix_notify(pdev, vector); + if (msix_enabled(pdev)) { + msix_notify(pdev, vector); + } } else { ivshmem_IntrStatus_write(s, 1); } @@ -713,16 +715,11 @@ static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size) /* Select the MSI-X vectors used by device. * ivshmem maps events to vectors statically, so * we just enable all vectors on init and after reset. */ -static void ivshmem_use_msix(IVShmemState * s) +static void ivshmem_msix_vector_use(IVShmemState *s) { PCIDevice *d = PCI_DEVICE(s); int i; - IVSHMEM_DPRINTF("%s, msix present: %d\n", __func__, msix_present(d)); - if (!msix_present(d)) { - return; - } - for (i = 0; i < s->vectors; i++) { msix_vector_use(d, i); } @@ -734,7 +731,9 @@ static void ivshmem_reset(DeviceState *d) s->intrstatus = 0; s->intrmask = 0; - ivshmem_use_msix(s); + if (ivshmem_has_feature(s, IVSHMEM_MSI)) { + ivshmem_msix_vector_use(s); + } } static int ivshmem_setup_interrupts(IVShmemState *s) @@ -748,7 +747,7 @@ static int ivshmem_setup_interrupts(IVShmemState *s) } IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors); - ivshmem_use_msix(s); + ivshmem_msix_vector_use(s); } return 0; @@ -1040,9 +1039,8 @@ static int ivshmem_post_load(void *opaque, int version_id) IVShmemState *s = opaque; if (ivshmem_has_feature(s, IVSHMEM_MSI)) { - ivshmem_use_msix(s); + ivshmem_msix_vector_use(s); } - return 0; } @@ -1070,7 +1068,7 @@ static int ivshmem_load_old(QEMUFile *f, void *opaque, int version_id) if (ivshmem_has_feature(s, IVSHMEM_MSI)) { msix_load(pdev, f); - ivshmem_use_msix(s); + ivshmem_msix_vector_use(s); } else { s->intrstatus = qemu_get_be32(f); s->intrmask = qemu_get_be32(f); -- cgit v1.1