On 09/30/2016 09:14 PM, Igor Mammedov wrote:
On Fri, 12 Aug 2016 14:54:05 +0800
Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx> wrote:
_FIT is required for hotplug support, guest will inquire the updated
device info from it if a hotplug event is received
As FIT buffer is not completely mapped into guest address space, so a
new function, Read FIT whose function index is 0xFFFFFFFF, is reserved
by QEMU to read the piece of FIT buffer. The buffer is concatenated
before _FIT return
Only issuer of UUID 2F10E7A4-9E91-11E4-89D3-123B93F75CBA can reserve
0xFFFFFFFF for some purposes.
So spec should be amended first or custom generated UUID should be used.
Okay.
I will change the changelog to reflect this fact and move the spec update
to this patch.
Refer to docs/specs/acpi-nvdimm.txt for detailed design
and amend docs to reflect that.
Already done in the spec, i will merge the spec changes into
this patch as you suggested later.
Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
---
hw/acpi/nvdimm.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)
diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
index 0e2b9f0..4bbd1e7 100644
--- a/hw/acpi/nvdimm.c
+++ b/hw/acpi/nvdimm.c
@@ -886,6 +886,87 @@ static void nvdimm_build_device_dsm(Aml *dev, uint32_t handle)
aml_append(dev, method);
}
+static void nvdimm_build_fit(Aml *dev)
+{
+ Aml *method, *pkg, *buf, *buf_size, *offset, *call_result;
+ Aml *whilectx, *ifcond, *ifctx, *fit;
+
+ buf = aml_local(0);
+ buf_size = aml_local(1);
+ fit = aml_local(2);
+
+ /* build helper function, RFIT. */
+ method = aml_method("RFIT", 1, AML_NOTSERIALIZED);
since you create named fields (global variable) in method scope,
you should make method serialized. Same goes for _FIT method.
Indeed, will fix.
+ aml_append(method, aml_create_dword_field(aml_buffer(4, NULL),
+ aml_int(0), "OFST"));
+
+ /* prepare input package. */
+ pkg = aml_package(1);
+ aml_append(method, aml_store(aml_arg(0), aml_name("OFST")));
+ aml_append(pkg, aml_name("OFST"));
+
+ /* call Read_FIT function. */
+ call_result = aml_call5(NVDIMM_COMMON_DSM,
+ aml_touuid("2F10E7A4-9E91-11E4-89D3-123B93F75CBA"
+ /* UUID for NVDIMM Root Device */),
+ aml_int(1) /* Revision 1 */,
+ aml_int(0xFFFFFFFF) /* Read FIT. */,
+ pkg, aml_int(0) /* for root device. */);
+ aml_append(method, aml_store(call_result, buf));
+
+ /* handle _DSM result. */
+ aml_append(method, aml_create_dword_field(buf,
+ aml_int(0) /* offset at byte 0 */, "STAU"));
+
+ /* if something is wrong during _DSM. */
+ ifcond = aml_equal(aml_int(0 /* Success */), aml_name("STAU"));
+ ifctx = aml_if(aml_lnot(ifcond));
+ aml_append(ifctx, aml_return(aml_buffer(0, NULL)));
+ aml_append(method, ifctx);
+ aml_append(method, aml_store(aml_sizeof(buf), buf_size));
+ aml_append(method, aml_subtract(buf_size,
+ aml_int(4) /* the size of "STAU" */,
+ buf_size));
Since you handle error case the same as EOF case you could replace
it with EOF case here and on qemu side of interface as well. That should
simplify code a bit as you won't need to strip out func_ret_status.
You mean returning NULL buffer if errors happen? However, the buffer is
generated by NVDIMM_COMMON_DSM function which is also used by _DSM based
on NVDIMM DSN specification, i.e, the 'func_ret_status' is needed anyway
no matter is successful or failed.
Or i missed your idea?
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