On Fri, 06 Oct 2023 15:15:56 -0700
Dave Jiang <dave.ji...@intel.com> wrote:
> Add a simple _DSM call support for the ACPI0017 device to return fake QTG
> ID values of 0 and 1 in all cases. This for _DSM plumbing testing from the OS.
>
> Following edited for readability
>
> Device (CXLM)
> {
> Name (_HID, "ACPI0017") // _HID: Hardware ID
> ...
> Method (_DSM, 4, Serialized) // _DSM: Device-Specific Method
> {
> If ((Arg0 == ToUUID ("f365f9a6-a7de-4071-a66a-b40c0b4f8e52")))
> {
> If ((Arg2 == Zero))
> {
> Return (Buffer (One) { 0x01 })
> }
>
> If ((Arg2 == One))
> {
> Return (Package (0x02)
> {
> One,
> Package (0x02)
> {
> Zero,
> One
> }
> })
> }
> }
> }
>
> Signed-off-by: Dave Jiang <dave.ji...@intel.com>
> Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com>
>
> --
You've picked up my bad habit / typo. Needs to be ---
to stop git picking up this text...
> v4: Change to package of ints rather than buffers. Also moved to 2 QTG IDs
> to improve kernel side testing. Tested on x86 qemu guest against kernel
> QTG ID _DSM parsing code to be upstreamed.
>
> v3: Fix output assignment to be BE host friendly. Fix typo in comment.
> According to the CXL spec, the DSM output should be 1 WORD to indicate
> the max suppoted QTG ID and a package of 0 or more WORDs for the QTG IDs.
> In this dummy impementation, we have first WORD with a 1 to indcate max
> supprted QTG ID of 1. And second WORD in a package to indicate the QTG
> ID of 0.
>
> v2: Minor edit to drop reference to switches in patch description.
> Message-Id: <20230904161847.18468-3-jonathan.came...@huawei.com>
> Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
Given it's changed in significant way should drop these.
Anyhow, the tests also need updating. I can do that and push out
a v5 with tests as well once I've tested.
I'm assuming need tweaked kernel code to test?
> ---
> hw/acpi/cxl.c | 69
> +++++++++++++++++++++++++++++++++++++++++++++++++
> hw/i386/acpi-build.c | 1 +
> include/hw/acpi/cxl.h | 1 +
> 3 files changed, 71 insertions(+)
>
> diff --git a/hw/acpi/cxl.c b/hw/acpi/cxl.c
> index 92b46bc9323b..9cd7905ea25a 100644
> --- a/hw/acpi/cxl.c
> +++ b/hw/acpi/cxl.c
> @@ -30,6 +30,75 @@
> #include "qapi/error.h"
> #include "qemu/uuid.h"
>
> +void build_cxl_dsm_method(Aml *dev)
> +{
> + Aml *method, *ifctx, *ifctx2;
> +
> + method = aml_method("_DSM", 4, AML_SERIALIZED);
> + {
> + Aml *function, *uuid;
> +
> + uuid = aml_arg(0);
> + function = aml_arg(2);
> + /* CXL spec v3.0 9.17.3.1 _DSM Function for Retrieving QTG ID */
> + ifctx = aml_if(aml_equal(
> + uuid, aml_touuid("F365F9A6-A7DE-4071-A66A-B40C0B4F8E52")));
> +
> + /* Function 0, standard DSM query function */
> + ifctx2 = aml_if(aml_equal(function, aml_int(0)));
> + {
> + uint8_t byte_list[1] = { 0x01 }; /* function 1 only */
> +
> + aml_append(ifctx2,
> + aml_return(aml_buffer(sizeof(byte_list), byte_list)));
> + }
> + aml_append(ifctx, ifctx2);
> +
> + /*
> + * Function 1
> + * Creating a package with static values. The max supported QTG ID
> will
> + * be 1 and recommended QTG IDs are 0 and then 1.
> + * The values here are statically created to simplify emulation.
> Values
> + * from a real BIOS would be determined by the performance of all the
> + * present CXL memory and then assigned.
> + */
> + ifctx2 = aml_if(aml_equal(function, aml_int(1)));
> + {
> + Aml *pak, *pak1;
> +
> + /*
> + * Return: A package containing two elements - a WORD that
> returns
> + * the maximum throttling group that the platform supports, and a
> + * package containing the QTG ID(s) that the platform recommends.
> + * Package {
> + * Max Supported QTG ID
> + * Package {QTG Recommendations}
> + * }
> + *
> + * While the SPEC specified WORD that hints at the value being
> + * 16bit, the ACPI dump of BIOS DSDT table showed that the values
> + * are integers with no specific size specification. aml_int()
> will
> + * be used for the values.
> + */
> + pak1 = aml_package(2);
> + /* Set QTG ID of 0 */
> + aml_append(pak1, aml_int(0));
> + /* Set QTG ID of 1 */
> + aml_append(pak1, aml_int(1));
> +
> + pak = aml_package(2);
> + /* Set Max QTG 1 */
> + aml_append(pak, aml_int(1));
> + aml_append(pak, pak1);
> +
> + aml_append(ifctx2, aml_return(pak));
> + }
> + aml_append(ifctx, ifctx2);
> + }
> + aml_append(method, ifctx);
> + aml_append(dev, method);
> +}
> +
> static void cedt_build_chbs(GArray *table_data, PXBCXLDev *cxl)
> {
> PXBDev *pxb = PXB_DEV(cxl);
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 95199c89008a..692af40b1a75 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1422,6 +1422,7 @@ static void build_acpi0017(Aml *table)
> method = aml_method("_STA", 0, AML_NOTSERIALIZED);
> aml_append(method, aml_return(aml_int(0x01)));
> aml_append(dev, method);
> + build_cxl_dsm_method(dev);
>
> aml_append(scope, dev);
> aml_append(table, scope);
> diff --git a/include/hw/acpi/cxl.h b/include/hw/acpi/cxl.h
> index acf441888683..8f22c71530d8 100644
> --- a/include/hw/acpi/cxl.h
> +++ b/include/hw/acpi/cxl.h
> @@ -25,5 +25,6 @@ void cxl_build_cedt(GArray *table_offsets, GArray
> *table_data,
> BIOSLinker *linker, const char *oem_id,
> const char *oem_table_id, CXLState *cxl_state);
> void build_cxl_osc_method(Aml *dev);
> +void build_cxl_dsm_method(Aml *dev);
>
> #endif
>
>
