From 4ebc736e9938a7e88ecc785734b17145bf802a56 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Thu, 11 Jun 2015 02:37:59 +0200 Subject: [PATCH] i386/acpi-build: fix PXB workarounds for unsupported BIOSes The patch apci: fix PXB behaviour if used with unsupported BIOS uses the following condition to see if a "PXB mem/IO chunk" has *not* been configured by the BIOS: (!range_base || range_base > range_limit) When this condition evaluates to true, said patch *omits* the corresponding entry from the _CRS. Later on the patch checks for the opposite condition (with the intent of *adding* entries to the _CRS if the "PXB mem/IO chunks" *have* been configured). Unfortunately, the condition was negated incorrectly: only the first ! operator was removed, which led to the nonsensical expression (range_base || range_base > range_limit) leading to bogus entries in the _CRS, and causing BSOD in Windows Server 2012 R2 when it runs on OVMF. The correct negative of the condition seen at the top is (range_base && range_base <= range_limit) Fix the expressions. Cc: Marcel Apfelbaum Cc: Michael S. Tsirkin Signed-off-by: Laszlo Ersek Reviewed-by: Marcel Apfelbaum Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/acpi-build.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 8fae3b9037..8e88aded9f 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -832,7 +832,7 @@ static Aml *build_crs(PCIHostState *host, * Work-around for old bioses * that do not support multiple root buses */ - if (range_base || range_base > range_limit) { + if (range_base && range_base <= range_limit) { aml_append(crs, aml_word_io(AML_MIN_FIXED, AML_MAX_FIXED, AML_POS_DECODE, AML_ENTIRE_RANGE, @@ -853,7 +853,7 @@ static Aml *build_crs(PCIHostState *host, * Work-around for old bioses * that do not support multiple root buses */ - if (range_base || range_base > range_limit) { + if (range_base && range_base <= range_limit) { aml_append(crs, aml_dword_memory(AML_POS_DECODE, AML_MIN_FIXED, AML_MAX_FIXED, AML_NON_CACHEABLE, @@ -864,7 +864,7 @@ static Aml *build_crs(PCIHostState *host, 0, range_limit - range_base + 1)); crs_range_insert(mem_ranges, range_base, range_limit); - } + } range_base = pci_bridge_get_base(dev, PCI_BASE_ADDRESS_MEM_PREFETCH); @@ -875,7 +875,7 @@ static Aml *build_crs(PCIHostState *host, * Work-around for old bioses * that do not support multiple root buses */ - if (range_base || range_base > range_limit) { + if (range_base && range_base <= range_limit) { aml_append(crs, aml_dword_memory(AML_POS_DECODE, AML_MIN_FIXED, AML_MAX_FIXED, AML_NON_CACHEABLE, -- 2.11.4.GIT