From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57325) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SFicY-0000An-Tj for qemu-devel@nongnu.org; Thu, 05 Apr 2012 05:04:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SFicS-0003D1-Ip for qemu-devel@nongnu.org; Thu, 05 Apr 2012 05:04:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46133) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SFicS-0003CK-Ag for qemu-devel@nongnu.org; Thu, 05 Apr 2012 05:04:40 -0400 Date: Thu, 5 Apr 2012 12:04:44 +0300 From: "Michael S. Tsirkin" Message-ID: <20120405090444.GB28229@redhat.com> References: <20120405050848.31461.10826.stgit@bling.home> <20120405055113.31461.45258.stgit@bling.home> <4F7D55FE.1070407@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F7D55FE.1070407@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/5] acpi_piix4: Only allow writes to PCI hotplug eject register List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: aliguori@us.ibm.com, gleb@redhat.com, jbaron@redhat.com, qemu-devel@nongnu.org, yamahata@valinux.co.jp, Alex Williamson , kraxel@redhat.com, pbonzini@redhat.com, aurelien@aurel32.net On Thu, Apr 05, 2012 at 10:21:18AM +0200, Igor Mammedov wrote: > On 04/05/2012 07:51 AM, Alex Williamson wrote: > >This is never read. We can also derive bus from the write handler, > >making this more inline with the other callbacks. Note that > >pciej_write was actually called with (PCIBus *)dev->bus, which is > >cast as a void* allowing us to pretend it's a BusState*. Fix this > >so we don't depend on the BusState location within PCIBus. > > > >Signed-off-by: Alex Williamson > >--- > > > > docs/specs/acpi_pci_hotplug.txt | 2 +- > > hw/acpi_piix4.c | 14 ++++---------- > > 2 files changed, 5 insertions(+), 11 deletions(-) > > > >diff --git a/docs/specs/acpi_pci_hotplug.txt b/docs/specs/acpi_pci_hotplug.txt > >index 1e2c8a2..1e61d19 100644 > >--- a/docs/specs/acpi_pci_hotplug.txt > >+++ b/docs/specs/acpi_pci_hotplug.txt > >@@ -28,7 +28,7 @@ PCI device eject (IO port 0xae08-0xae0b, 4-byte access): > > ---------------------------------------- > > > > Used by ACPI BIOS _EJ0 method to request device removal. One bit per slot. > >-Reads return 0. > >+Read-only. > Write-only perhaps? Yes, let's also specify what happens in practice. I think it is 'Guest should never read this register, in practice 0 is returned'. > > > > PCI removability status (IO port 0xae0c-0xae0f, 4-byte access): > > ----------------------------------------------- > >diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c > >index 44d1423..6ee832a 100644 > >--- a/hw/acpi_piix4.c > >+++ b/hw/acpi_piix4.c > >@@ -487,15 +487,11 @@ static uint32_t pci_down_read(void *opaque, uint32_t addr) > > return val; > > } > > > >-static uint32_t pciej_read(void *opaque, uint32_t addr) > >-{ > >- PIIX4_DPRINTF("pciej read %x\n", addr); > >- return 0; > >-} > >- > what will happen if bios tries to read from reg? I think it currently gets 0. > > static void pciej_write(void *opaque, uint32_t addr, uint32_t val) > > { > >- BusState *bus = opaque; > >+ PIIX4PMState *s = opaque; > >+ PCIDevice *dev =&s->dev; > >+ BusState *bus = qdev_get_parent_bus(&dev->qdev); > > DeviceState *qdev, *next; > > int slot = ffs(val) - 1; > > > >@@ -507,7 +503,6 @@ static void pciej_write(void *opaque, uint32_t addr, uint32_t val) > > } > > } > > > >- > > PIIX4_DPRINTF("pciej write %x<== %d\n", addr, val); > > } > > > >@@ -547,8 +542,7 @@ static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s) > > register_ioport_read(PCI_UP_BASE, 4, 4, pci_up_read, s); > > register_ioport_read(PCI_DOWN_BASE, 4, 4, pci_down_read, s); > > > >- register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, bus); > >- register_ioport_read(PCI_EJ_BASE, 4, 4, pciej_read, bus); > >+ register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, s); > > > > register_ioport_write(PCI_RMV_BASE, 4, 4, pcirmv_write, s); > > register_ioport_read(PCI_RMV_BASE, 4, 4, pcirmv_read, s); > > > > -- > ----- > Igor