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Re: [Qemu-devel] [PATCH] hw/i386/acpi-build: place qword descriptors in
From: |
Marcel Apfelbaum |
Subject: |
Re: [Qemu-devel] [PATCH] hw/i386/acpi-build: place qword descriptors in bridge _CRS's when needed |
Date: |
Mon, 14 Mar 2016 10:07:17 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 |
On 03/14/2016 03:42 AM, Laszlo Ersek wrote:
In build_crs(), the calculation & merging of the ranges already happens in
64-bit, but the entry boundaries are silently truncated to 32-bit in the
call to aml_dword_memory(). Use aml_qword_memory() when necessary -- this
fixes 64-bit BARs behind PXBs.
Hi Laszlo,
Thanks for the patch.
Please see below some comments.
Cc: Marcel Apfelbaum <address@hidden>
Cc: Michael S. Tsirkin <address@hidden>
Signed-off-by: Laszlo Ersek <address@hidden>
---
hw/i386/acpi-build.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b88800883944..3157cc36db98 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -938,13 +938,25 @@ static Aml *build_crs(PCIHostState *host,
crs_range_merge(host_mem_ranges);
for (i = 0; i < host_mem_ranges->len; i++) {
+ Aml *mem;
+ uint64_t length;
+
entry = g_ptr_array_index(host_mem_ranges, i);
- aml_append(crs,
- aml_dword_memory(AML_POS_DECODE, AML_MIN_FIXED,
- AML_MAX_FIXED, AML_NON_CACHEABLE,
- AML_READ_WRITE,
- 0, entry->base, entry->limit, 0,
- entry->limit - entry->base + 1));
+ length = entry->limit - entry->base + 1;
+ if (entry->limit <= UINT32_MAX && length <= UINT32_MAX) {
Why do we need to check the length if we've already checked the entry->limit ?
+ mem = aml_dword_memory(AML_POS_DECODE, AML_MIN_FIXED,
+ AML_MAX_FIXED, AML_NON_CACHEABLE,
+ AML_READ_WRITE,
+ 0, entry->base, entry->limit, 0,
+ length);
+ } else {
+ mem = aml_qword_memory(AML_POS_DECODE, AML_MIN_FIXED,
+ AML_MAX_FIXED, AML_NON_CACHEABLE,
+ AML_READ_WRITE,
+ 0, entry->base, entry->limit, 0,
+ length);
+ }
+ aml_append(crs, mem);
crs_range_insert(mem_ranges, entry->base, entry->limit);
}
g_ptr_array_free(host_mem_ranges, true);
I think it is correct, but this also means the mem_ranges array can have 64-bit
ranges =>
the 'crs_replace_with_free_ranges' call for mem_ranges is also incorrect because
it assumes all the ranges are between [pci->w32.begin, pci->w32.end - 1].
And of course this would also interfere with the crs building for pci->w64.
We can't assign all the [pci->w64.begin, pci->w64.end - 1] range to bus 0
anymore,
we need to take out the ranges used by pxbs. (same as we did for pci->w32)
Indeed, this is one of the pxb limitations, supporting only 32bit BARs and your
patch is going in the right direction.
Do you want to continue it? I will not be available for one week, but I can
take care of it
after that.
Thanks!
Marcel