[Qemu-devel] [PATCH] map 64-bit PCI BARs at location provided by emulator
Currently 64-bit PCI BARs are unconditionally mapped by BIOS right
over 4G + RamSizeOver4G location, which doesn't allow to reserve
extra space before 64-bit PCI window. For memory hotplug an extra
RAM space might be reserved after present 64-bit RAM end and BIOS
should map 64-bit PCI BARs after it.
Introduce "etc/pcimem64-minimum-addres" romfile to provide BIOS
a hint where it should start mapping of 64-bit PCI BARs.
If romfile is missing BIOS reverts to legacy behavior and starts
mapping right after high memory.
Signed-off-by: Igor Mammedov
v3:
* rename "etc/pcimem64-start" to "etc/pcimem64-minimum-addres"
v2:
* place 64-bit window behind high RAM end if "etc/pcimem64-start"
points below it.
---
src/fw/pciinit.c | 13 -
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
index b29db99..64a37c3 100644
--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -18,6 +18,8 @@
#include "paravirt.h" // RamSize
#include "string.h" // memset
#include "util.h" // pci_setup
+#include "byteorder.h" // le64_to_cpu
+#include "romfile.h" // romfile_loadint
#define PCI_DEVICE_MEM_MIN 0x1000
#define PCI_BRIDGE_IO_MIN 0x1000
@@ -764,6 +766,15 @@ static void pci_bios_map_devices(struct pci_bus *busses)
{
if (pci_bios_init_root_regions(busses)) {
struct pci_region r64_mem, r64_pref;
+u64 ram64_end = 0x1ULL + RamSizeOver4G;
+u64 base64 =
le64_to_cpu(romfile_loadint("etc/pcimem64-minimum-address",
+ ram64_end));
+if (base64 < ram64_end) {
+dprintf(1, "ignorig etc/pcimem64-minimum-address [0x%llx] below "
+ "present RAM, placing 64-bit PCI window behind RAM end:
"
+ "0x%llx", base64, ram64_end);
+base64 = ram64_end;
+}
r64_mem.list.first = NULL;
r64_pref.list.first = NULL;
pci_region_migrate_64bit_entries(&busses[0].r[PCI_REGION_TYPE_MEM],
@@ -779,7 +790,7 @@ static void pci_bios_map_devices(struct pci_bus *busses)
u64 align_mem = pci_region_align(&r64_mem);
u64 align_pref = pci_region_align(&r64_pref);
-r64_mem.base = ALIGN(0x1LL + RamSizeOver4G, align_mem);
+r64_mem.base = ALIGN(base64, align_mem);
r64_pref.base = ALIGN(r64_mem.base + sum_mem, align_pref);
pcimem64_start = r64_mem.base;
pcimem64_end = r64_pref.base + sum_pref;
--
1.7.1
Re: [Qemu-devel] [PATCH] map 64-bit PCI BARs at location provided by emulator
On Fri, 11 Oct 2013 14:35:50 +0200
Gerd Hoffmann wrote:
> On Fr, 2013-10-11 at 12:19 +0200, Igor Mammedov wrote:
> > Currently 64-bit PCI BARs are unconditionally mapped by BIOS right
> > over 4G + RamSizeOver4G location, which doesn't allow to reserve
> > extra space before 64-bit PCI window. For memory hotplug an extra
> > RAM space might be reserved after present 64-bit RAM end and BIOS
> > should map 64-bit PCI BARs after it.
> >
> > Introduce "etc/pcimem64-start" romfile to provide BIOS a hint
> > where it should start mapping of 64-bit PCI BARs. If romfile is
> > missing BIOS reverts to legacy behavior and starts mapping right
> > after high memory.
>
> Looks good overall.
>
>
> > struct pci_region r64_mem, r64_pref;
> > +u64 base64 = le64_to_cpu(romfile_loadint("etc/pcimem64-start",
> > + 0x1ULL + RamSizeOver4G));
>
> Should we sanity-check base64 maybe?
> Make sure it isn't smaller than 0x1ULL + RamSizeOver4G?
If it would be less than 0x1ULL + RamSizeOver4G then it would mean
that QEMU for some reason decided to overshadow present RAM with PCI hole.
It would add a couple of extra bytes to BIOS and point where it should fail
or at least print a warning that nobody will read at runtime.
I think it's better to assert on QEMU side and abort even before guest
started if it's considered as error.
>
> cheers,
> Gerd
>
>
>
Re: [Qemu-devel] [PATCH] map 64-bit PCI BARs at location provided by emulator
On Fr, 2013-10-11 at 12:19 +0200, Igor Mammedov wrote:
> Currently 64-bit PCI BARs are unconditionally mapped by BIOS right
> over 4G + RamSizeOver4G location, which doesn't allow to reserve
> extra space before 64-bit PCI window. For memory hotplug an extra
> RAM space might be reserved after present 64-bit RAM end and BIOS
> should map 64-bit PCI BARs after it.
>
> Introduce "etc/pcimem64-start" romfile to provide BIOS a hint
> where it should start mapping of 64-bit PCI BARs. If romfile is
> missing BIOS reverts to legacy behavior and starts mapping right
> after high memory.
Looks good overall.
> struct pci_region r64_mem, r64_pref;
> +u64 base64 = le64_to_cpu(romfile_loadint("etc/pcimem64-start",
> + 0x1ULL + RamSizeOver4G));
Should we sanity-check base64 maybe?
Make sure it isn't smaller than 0x1ULL + RamSizeOver4G?
cheers,
Gerd
[Qemu-devel] [PATCH] map 64-bit PCI BARs at location provided by emulator
Currently 64-bit PCI BARs are unconditionally mapped by BIOS right
over 4G + RamSizeOver4G location, which doesn't allow to reserve
extra space before 64-bit PCI window. For memory hotplug an extra
RAM space might be reserved after present 64-bit RAM end and BIOS
should map 64-bit PCI BARs after it.
Introduce "etc/pcimem64-start" romfile to provide BIOS a hint
where it should start mapping of 64-bit PCI BARs. If romfile is
missing BIOS reverts to legacy behavior and starts mapping right
after high memory.
Signed-off-by: Igor Mammedov
---
src/fw/pciinit.c |6 +-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c
index b29db99..f056633 100644
--- a/src/fw/pciinit.c
+++ b/src/fw/pciinit.c
@@ -18,6 +18,8 @@
#include "paravirt.h" // RamSize
#include "string.h" // memset
#include "util.h" // pci_setup
+#include "byteorder.h" // le64_to_cpu
+#include "romfile.h" // romfile_loadint
#define PCI_DEVICE_MEM_MIN 0x1000
#define PCI_BRIDGE_IO_MIN 0x1000
@@ -764,6 +766,8 @@ static void pci_bios_map_devices(struct pci_bus *busses)
{
if (pci_bios_init_root_regions(busses)) {
struct pci_region r64_mem, r64_pref;
+u64 base64 = le64_to_cpu(romfile_loadint("etc/pcimem64-start",
+ 0x1ULL + RamSizeOver4G));
r64_mem.list.first = NULL;
r64_pref.list.first = NULL;
pci_region_migrate_64bit_entries(&busses[0].r[PCI_REGION_TYPE_MEM],
@@ -779,7 +783,7 @@ static void pci_bios_map_devices(struct pci_bus *busses)
u64 align_mem = pci_region_align(&r64_mem);
u64 align_pref = pci_region_align(&r64_pref);
-r64_mem.base = ALIGN(0x1LL + RamSizeOver4G, align_mem);
+r64_mem.base = ALIGN(base64, align_mem);
r64_pref.base = ALIGN(r64_mem.base + sum_mem, align_pref);
pcimem64_start = r64_mem.base;
pcimem64_end = r64_pref.base + sum_pref;
--
1.7.1
