On 11/05/2015 05:58 PM, Igor Mammedov wrote:
On Mon, 2 Nov 2015 17:13:27 +0800
Xiao Guangrong <address@hidden> wrote:
A page staring from 0xFF00000 and IO port 0x0a18 - 0xa1b in guest are
^^ missing one 0???
reserved for NVDIMM ACPI emulation, refer to docs/specs/acpi_nvdimm.txt
for detailed design
A parameter, 'nvdimm-support', is introduced for PIIX4_PM and ICH9-LPC
that controls if nvdimm support is enabled, it is true on default and
it is false on 2.4 and its earlier version to keep compatibility
Signed-off-by: Xiao Guangrong <address@hidden>
[...]
@@ -33,6 +33,15 @@
*/
#define MIN_NAMESPACE_LABEL_SIZE (128UL << 10)
+/*
+ * A page staring from 0xFF00000 and IO port 0x0a18 - 0xa1b in guest are
^^^ missing 0 or value in define below has
an extra 0
+ * reserved for NVDIMM ACPI emulation, refer to docs/specs/acpi_nvdimm.txt
+ * for detailed design.
+ */
+#define NVDIMM_ACPI_MEM_BASE 0xFF000000ULL
it still maps RAM at arbitrary place,
that's the reason why VMGenID patches hasn't been merged for
more than several months.
I'm not against of using (more exactly I'm for it) direct mapping
but we should reach consensus when and how to use it first.
I'd wouldn't use addresses below 4G as it may be used firmware or
legacy hardware and I won't bet that 0xFF000000ULL won't conflict
with anything.
An alternative place to allocate reserve from could be high memory.
For pc we have "reserved-memory-end" which currently makes sure
that hotpluggable memory range isn't used by firmware.
How about making API that allows to map additional memory
ranges before reserved-memory-end and pushes it up as mappings are
added.
That what i did in the v1/v2 versions, however, as you noticed, using 64-bit
address in ACPI in QEMU is not a easy work - we can not simply make
SSDT.rev = 2 to apply 64 bit address, the reason i have documented in
v3's changelog:
3) we figure out a unused memory hole below 4G that is 0xFF00000 ~
0xFFF00000, this range is large enough for NVDIMM ACPI as build 64-bit
ACPI SSDT/DSDT table will break windows XP.
BTW, only make SSDT.rev = 2 can not work since the width is only
depended
on DSDT.rev based on 19.6.28 DefinitionBlock (Declare Definition Block)
in ACPI spec:
| Note: For compatibility with ACPI versions before ACPI 2.0, the bit
| width of Integer objects is dependent on the ComplianceRevision of the DSDT.
| If the ComplianceRevision is less than 2, all integers are restricted to 32
| bits. Otherwise, full 64-bit integers are used. The version of the DSDT sets
| the global integer width for all integers, including integers in SSDTs.
4) use the lowest ACPI spec version to document AML terms.
The only way introducing 64 bit address is adding XSDT support that what
Michael did before, however, it seems it need great efforts to do it as
it will break OVMF. It's a long term workload. :(