From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH 2/4] kvm tools: Fix PCI probing Date: Thu, 28 Jul 2011 12:01:53 +0300 Message-ID: <1311843715-5464-2-git-send-email-levinsasha928@gmail.com> References: <1311843715-5464-1-git-send-email-levinsasha928@gmail.com> Cc: kvm@vger.kernel.org, mingo@elte.hu, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com, Sasha Levin To: penberg@kernel.org Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:34882 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755185Ab1G1JDC (ORCPT ); Thu, 28 Jul 2011 05:03:02 -0400 Received: by fxh19 with SMTP id 19so1069156fxh.19 for ; Thu, 28 Jul 2011 02:03:01 -0700 (PDT) In-Reply-To: <1311843715-5464-1-git-send-email-levinsasha928@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: PCI BAR probing is done in four steps: 1. Read address (and flags). 2. Mask BAR. 3. Read BAR again - Now the expected result is the size of the BAR. 4. Mask BAR with address. So far, we have only took care of the first step. This means that the kernel was using address as the size, causing a PCI allocation blunder. This patch fixes the issue by passing a proper size after masking. Signed-off-by: Sasha Levin --- tools/kvm/include/kvm/pci.h | 1 + tools/kvm/pci.c | 57 +++++++++++++++++++++++++++++++++++++++---- 2 files changed, 53 insertions(+), 5 deletions(-) diff --git a/tools/kvm/include/kvm/pci.h b/tools/kvm/include/kvm/pci.h index 6ad4426..a7532e3 100644 --- a/tools/kvm/include/kvm/pci.h +++ b/tools/kvm/include/kvm/pci.h @@ -51,5 +51,6 @@ struct pci_device_header { void pci__init(void); void pci__register(struct pci_device_header *dev, u8 dev_num); +u32 pci_get_io_space_block(void); #endif /* KVM__PCI_H */ diff --git a/tools/kvm/pci.c b/tools/kvm/pci.c index a1ad8ba..799536e3 100644 --- a/tools/kvm/pci.c +++ b/tools/kvm/pci.c @@ -5,11 +5,23 @@ #include #define PCI_MAX_DEVICES 256 +#define PCI_IO_SIZE 0x100 static struct pci_device_header *pci_devices[PCI_MAX_DEVICES]; static struct pci_config_address pci_config_address; +/* This is within our PCI gap */ +static u32 io_space_blocks = 0xE1000000; + +u32 pci_get_io_space_block(void) +{ + u32 block = io_space_blocks; + io_space_blocks += PCI_IO_SIZE; + + return block; +} + static void *pci_config_address_ptr(u16 port) { unsigned long offset; @@ -44,11 +56,6 @@ static struct ioport_operations pci_config_address_ops = { .io_out = pci_config_address_out, }; -static bool pci_config_data_out(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count) -{ - return true; -} - static bool pci_device_exists(u8 bus_number, u8 device_number, u8 function_number) { struct pci_device_header *dev; @@ -67,6 +74,46 @@ static bool pci_device_exists(u8 bus_number, u8 device_number, u8 function_numbe return dev != NULL; } +static bool pci_config_data_out(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count) +{ + unsigned long start; + u8 dev_num; + + /* + * If someone accesses PCI configuration space offsets that are not + * aligned to 4 bytes, it uses ioports to signify that. + */ + start = port - PCI_CONFIG_DATA; + + dev_num = pci_config_address.device_number; + + if (pci_device_exists(0, dev_num, 0)) { + unsigned long offset; + + offset = start + (pci_config_address.register_number << 2); + if (offset < sizeof(struct pci_device_header)) { + void *p = pci_devices[dev_num]; + u32 sz = PCI_IO_SIZE; + + /* + * If the kernel masks the BAR it would expect to find the + * size of the BAR there next time it reads from it. + * When the kernel got the size it would write the address + * back. + */ + if ((offset >= offsetof(struct pci_device_header, bar[0])) && + (offset <= offsetof(struct pci_device_header, bar[6]))) { + if (*(u32 *)(p + offset)) + memcpy(p + offset, &sz, sizeof(sz)); + } else if (*(u32 *)(p + offset)) { + memcpy(p + offset, data, size); + } + } + } + + return true; +} + static bool pci_config_data_in(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count) { unsigned long start; -- 1.7.6