Re: [Qemu-devel] [PATCH v3 07/13] tests: acpi: add acpi_find_rsdp_address_uefi() helper

[Wei Yang <richardw.yang@linux.intel.com>]

On Thu, Apr 25, 2019 at 07:34:43AM +0200, Igor Mammedov wrote:
>introduce UEFI specific counterpart to acpi_find_rsdp_address()
>that will help to find RSDP address when [OA]VMF is used as
>firmware. It requires guest firmware or other guest app to place
>1Mb aligned UefiTestSupport structure (defined in this patch)
>in RAM with UefiTestSupport::signature_guid set to
>AB87A6B1-2034-BDA0-71BD-375007757785

Just curious about where we get this signature? Randomly generated?

>
>Signed-off-by: Igor Mammedov <imammedo@redhat.com>
>Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>

>---
>v3:
>  * fix checkpatch error (separate opening brace from values in AcpiTestSupportGuid initializer)
>v2:
>  * Laszlo Ersek <lersek@redhat.com>
>    - s/uefi_find_rsdp_addr/acpi_find_rsdp_address_uefi/
>    - use GUID_SIZE instead of opencodding size
>    - make AcpiTestSupportGuid const
>    - s/TCI/TCG/
>---
> tests/acpi-utils.h |  2 ++
> tests/acpi-utils.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 46 insertions(+)
>
>diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h
>index 75f78f2..dcfa721 100644
>--- a/tests/acpi-utils.h
>+++ b/tests/acpi-utils.h
>@@ -46,6 +46,8 @@ typedef struct {
> 
> uint8_t acpi_calc_checksum(const uint8_t *data, int len);
> uint32_t acpi_find_rsdp_address(QTestState *qts);
>+uint64_t acpi_find_rsdp_address_uefi(QTestState *qts, uint64_t start,
>+                                     uint64_t size);
> void acpi_fetch_rsdp_table(QTestState *qts, uint64_t addr, uint8_t *rsdp_table);
> void acpi_fetch_table(QTestState *qts, uint8_t **aml, uint32_t *aml_len,
>                       const uint8_t *addr_ptr, const char *sig,
>diff --git a/tests/acpi-utils.c b/tests/acpi-utils.c
>index 2dd4fe0..197af82 100644
>--- a/tests/acpi-utils.c
>+++ b/tests/acpi-utils.c
>@@ -99,3 +99,47 @@ void acpi_fetch_table(QTestState *qts, uint8_t **aml, uint32_t *aml_len,
>         g_assert(!acpi_calc_checksum(*aml, *aml_len));
>     }
> }
>+
>+#define GUID_SIZE 16
>+static const uint8_t AcpiTestSupportGuid[GUID_SIZE] = {
>+       0xb1, 0xa6, 0x87, 0xab,
>+       0x34, 0x20,
>+       0xa0, 0xbd,
>+       0x71, 0xbd, 0x37, 0x50, 0x07, 0x75, 0x77, 0x85 };
>+
>+typedef struct {
>+    uint8_t signature_guid[GUID_SIZE];
>+    uint64_t rsdp10;
>+    uint64_t rsdp20;
>+} __attribute__((packed)) UefiTestSupport;
>+
>+/* Wait at most 600 seconds (test is slow with TCG and --enable-debug) */
>+#define TEST_DELAY (1 * G_USEC_PER_SEC / 10)
>+#define TEST_CYCLES MAX((600 * G_USEC_PER_SEC / TEST_DELAY), 1)
>+#define MB 0x100000ULL
>+uint64_t acpi_find_rsdp_address_uefi(QTestState *qts, uint64_t start,
>+                                     uint64_t size)
>+{
>+    int i, j;
>+    uint8_t data[GUID_SIZE];
>+
>+    for (i = 0; i < TEST_CYCLES; ++i) {
>+        for (j = 0; j < size / MB; j++) {
>+            /* look for GUID at every 1Mb block */
>+            uint64_t addr = start + j * MB;
>+
>+            qtest_memread(qts, addr, data, sizeof(data));
>+            if (!memcmp(AcpiTestSupportGuid, data, sizeof(data))) {
>+                UefiTestSupport ret;
>+
>+                qtest_memread(qts, addr, &ret, sizeof(ret));
>+                ret.rsdp10 = le64_to_cpu(ret.rsdp10);
>+                ret.rsdp20 = le64_to_cpu(ret.rsdp20);
>+                return ret.rsdp20 ? ret.rsdp20 : ret.rsdp10;
>+            }
>+        }
>+        g_usleep(TEST_DELAY);
>+    }
>+    g_assert_not_reached();
>+    return 0;
>+}
>-- 
>2.7.4

-- 
Wei Yang
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