From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: [PATCH v2 1/5] hvmloader: Correct bug in low mmio region accounting Date: Tue, 18 Jun 2013 17:46:20 +0100 Message-ID: <1371573984-28514-1-git-send-email-george.dunlap@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: George Dunlap , Ian Jackson , Stefano Stabellini , Ian Campbell , Hanweidong List-Id: xen-devel@lists.xenproject.org When deciding whether to map a device in low MMIO space (<4GiB), hvmloader compares it with "mmio_left", which is set to the size of the low MMIO range (pci_mem_end - pci_mem_start). However, even if it does map a device in high MMIO space, it still removes the size of its BAR from mmio_left. This patch first changes the name of this variable to "low_mmio_left" to distinguish it from generic MMIO, and corrects the logic to only subtract the size of the BAR for devices maped in the low MMIO region. Also make low_mmio_left unsigned, and don't allow it to go negative. Since its main use is to be compared to a 64-bit unsigned int, this may have undefined (and in practice almost certainly incorrect) results. Not subtracting is OK because if there's not enough room, it won't actually be mapped. Signed-off-by: George Dunlap CC: Ian Jackson CC: Ian Campbell CC: Stefano Stabellini CC: Hanweidong --- tools/firmware/hvmloader/pci.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c index c78d4d3..8691a19 100644 --- a/tools/firmware/hvmloader/pci.c +++ b/tools/firmware/hvmloader/pci.c @@ -38,11 +38,10 @@ void pci_setup(void) { uint8_t is_64bar, using_64bar, bar64_relocate = 0; uint32_t devfn, bar_reg, cmd, bar_data, bar_data_upper; - uint64_t base, bar_sz, bar_sz_upper, mmio_total = 0; + uint64_t base, bar_sz, bar_sz_upper, low_mmio_left, mmio_total = 0; uint32_t vga_devfn = 256; uint16_t class, vendor_id, device_id; unsigned int bar, pin, link, isa_irq; - int64_t mmio_left; /* Resources assignable to PCI devices via BARs. */ struct resource { @@ -244,7 +243,7 @@ void pci_setup(void) io_resource.base = 0xc000; io_resource.max = 0x10000; - mmio_left = pci_mem_end - pci_mem_start; + low_mmio_left = pci_mem_end - pci_mem_start; /* Assign iomem and ioport resources in descending order of size. */ for ( i = 0; i < nr_bars; i++ ) @@ -253,7 +252,7 @@ void pci_setup(void) bar_reg = bars[i].bar_reg; bar_sz = bars[i].bar_sz; - using_64bar = bars[i].is_64bar && bar64_relocate && (mmio_left < bar_sz); + using_64bar = bars[i].is_64bar && bar64_relocate && (low_mmio_left < bar_sz); bar_data = pci_readl(devfn, bar_reg); if ( (bar_data & PCI_BASE_ADDRESS_SPACE) == @@ -273,9 +272,10 @@ void pci_setup(void) } else { resource = &mem_resource; + if ( bar_sz <= low_mmio_left ) + low_mmio_left -= bar_sz; bar_data &= ~PCI_BASE_ADDRESS_MEM_MASK; } - mmio_left -= bar_sz; } else { -- 1.7.9.5