qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Aditya Gupta <adityag@linux.ibm.com>
To: <qemu-devel@nongnu.org>
Cc: qemu-ppc@nongnu.org, "Nicholas Piggin" <npiggin@gmail.com>,
	"Daniel Henrique Barboza" <danielhb413@gmail.com>,
	"Harsh Prateek Bora" <harshpb@linux.ibm.com>,
	"Sourabh Jain" <sourabhjain@linux.ibm.com>,
	"Mahesh J Salgaonkar" <mahesh@linux.ibm.com>,
	"Hari Bathini" <hbathini@linux.ibm.com>,
	"Chinmay Rath" <rathc@linux.ibm.com>,
	"Thomas Huth" <thuth@redhat.com>,
	"Shivang Upadhyay" <shivangu@linux.ibm.com>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [PATCH v5 5/8] hw/ppc: Pass dump-sizes property for fadump in device tree
Date: Tue, 21 Oct 2025 19:18:15 +0530	[thread overview]
Message-ID: <20251021134823.1861675-6-adityag@linux.ibm.com> (raw)
In-Reply-To: <20251021134823.1861675-1-adityag@linux.ibm.com>

Platform (ie. QEMU) is expected to pass few device tree properties for
details for fadump:

  * "ibm,configure-kernel-dump-sizes": Space required to store dump data
    for firmware provided dump sections (ie. CPU & HPTE regions)
  * "ibm,configure-kernel-dump-version": Versions of fadump supported

Pass the above device tree nodes so that kernel can reserve sufficient
space for preserving the CPU state data

Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
---
 hw/ppc/spapr.c        | 57 +++++++++++++++++++++++++++++++++++++++++++
 hw/ppc/spapr_fadump.c |  6 ++---
 2 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 97ab6bebd25c..d40d5a9dcde5 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -900,6 +900,61 @@ static int spapr_dt_rng(void *fdt)
     return ret ? -1 : 0;
 }
 
+static void spapr_dt_rtas_fadump(SpaprMachineState *spapr, void *fdt, int rtas)
+{
+    MachineState *ms = MACHINE(spapr);
+    MachineClass *mc = MACHINE_GET_CLASS(ms);
+
+    uint32_t max_possible_cpus = mc->possible_cpu_arch_ids(ms)->len;
+    uint64_t fadump_cpu_state_size = 0;
+    uint16_t fadump_versions[2] = {
+        FADUMP_VERSION /* min supported version */,
+        FADUMP_VERSION /* max supported version */
+    };
+    uint32_t fadump_rgn_sizes[2][3] = {
+        {
+            cpu_to_be32(FADUMP_CPU_STATE_DATA),
+            0, 0 /* Calculated later */
+        },
+        {
+            cpu_to_be32(FADUMP_HPTE_REGION),
+            0, 0 /* HPTE region not implemented */
+        }
+    };
+
+    /*
+     * CPU State Data contains multiple fields such as header, num_cpus and
+     * register entries
+     *
+     * Calculate the maximum CPU State Data size, according to maximum
+     * possible CPUs the QEMU VM can have
+     *
+     * This calculation must match the 'cpu_state_len' calculation done in
+     * 'populate_cpu_state_data' in spapr_fadump.c
+     */
+    fadump_cpu_state_size += sizeof(struct FadumpRegSaveAreaHeader);
+    fadump_cpu_state_size += 0xc;                      /* padding as in PAPR */
+    fadump_cpu_state_size += sizeof(uint32_t);         /* num_cpus */
+    fadump_cpu_state_size += max_possible_cpus   *     /* reg entries */
+                             FADUMP_PER_CPU_REG_ENTRIES *
+                             sizeof(struct FadumpRegEntry);
+
+    /* Set maximum size for CPU state data region */
+    assert(fadump_rgn_sizes[0][0] == cpu_to_be32(FADUMP_CPU_STATE_DATA));
+
+    /* Upper 32 bits of size, usually 0 */
+    fadump_rgn_sizes[0][1] = cpu_to_be32(fadump_cpu_state_size >> 32);
+
+    /* Lower 32 bits of size */
+    fadump_rgn_sizes[0][2] = cpu_to_be32(fadump_cpu_state_size & 0xffffffff);
+
+    /* Add device tree properties required from platform for fadump */
+    _FDT((fdt_setprop(fdt, rtas, "ibm,configure-kernel-dump-version",
+                    fadump_versions, sizeof(fadump_versions))));
+    _FDT((fdt_setprop(fdt, rtas, "ibm,configure-kernel-dump-sizes",
+                    fadump_rgn_sizes, sizeof(fadump_rgn_sizes))));
+}
+
 static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
 {
     MachineState *ms = MACHINE(spapr);
@@ -1015,6 +1070,8 @@ static void spapr_dt_rtas(SpaprMachineState *spapr, void *fdt)
     _FDT(fdt_setprop(fdt, rtas, "ibm,lrdr-capacity",
                      lrdr_capacity, sizeof(lrdr_capacity)));
 
+    spapr_dt_rtas_fadump(spapr, fdt, rtas);
+
     spapr_dt_rtas_tokens(fdt, rtas);
 }
 
diff --git a/hw/ppc/spapr_fadump.c b/hw/ppc/spapr_fadump.c
index fdd49291483e..fa3aeac94cb7 100644
--- a/hw/ppc/spapr_fadump.c
+++ b/hw/ppc/spapr_fadump.c
@@ -492,7 +492,7 @@ static void *get_cpu_state_data(uint64_t *cpu_state_len)
     *cpu_state_len = 0;
     *cpu_state_len += sizeof(reg_save_hdr);     /* reg save header */
     *cpu_state_len += 0xc;                      /* padding as in PAPR */
-    *cpu_state_len += sizeof(__be32);           /* num_cpus */
+    *cpu_state_len += sizeof(num_cpus);         /* num_cpus */
     *cpu_state_len += reg_entries_size;         /* reg entries */
 
     cpu_state_buffer = g_malloc(*cpu_state_len);
@@ -503,8 +503,8 @@ static void *get_cpu_state_data(uint64_t *cpu_state_len)
 
     /* Write num_cpus */
     num_cpus = cpu_to_be32(num_cpus);
-    memcpy(cpu_state_buffer + offset, &num_cpus, sizeof(__be32));
-    offset += sizeof(__be32);
+    memcpy(cpu_state_buffer + offset, &num_cpus, sizeof(num_cpus));
+    offset += sizeof(num_cpus);
 
     /* Write the register entries */
     memcpy(cpu_state_buffer + offset, reg_entries, reg_entries_size);
-- 
2.51.0



  parent reply	other threads:[~2025-10-21 13:50 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-21 13:48 [PATCH v5 0/8] Implement Firmware Assisted Dump for PSeries Aditya Gupta
2025-10-21 13:48 ` [PATCH v5 1/8] hw/ppc: Implement fadump register command Aditya Gupta
2025-10-23  8:16   ` Sourabh Jain
2025-10-23 11:06     ` Aditya Gupta
2025-10-21 13:48 ` [PATCH v5 2/8] hw/ppc: Trigger Fadump boot if fadump is registered Aditya Gupta
2025-10-23  8:18   ` Sourabh Jain
2025-10-21 13:48 ` [PATCH v5 3/8] hw/ppc: Preserve memory regions registered for fadump Aditya Gupta
2025-10-23  8:39   ` Sourabh Jain
2025-10-21 13:48 ` [PATCH v5 4/8] hw/ppc: Implement saving CPU state in Fadump Aditya Gupta
2025-10-23  9:05   ` Sourabh Jain
2025-10-23 11:11     ` Aditya Gupta
2025-10-23 11:16       ` Sourabh Jain
2025-10-23 11:20         ` Harsh Prateek Bora
2025-10-23 11:15     ` Aditya Gupta
2025-10-21 13:48 ` Aditya Gupta [this message]
2025-10-23  9:08   ` [PATCH v5 5/8] hw/ppc: Pass dump-sizes property for fadump in device tree Sourabh Jain
2025-10-21 13:48 ` [PATCH v5 6/8] hw/ppc: Enable fadump for PSeries Aditya Gupta
2025-10-23  9:08   ` Sourabh Jain
2025-10-23 11:17     ` Aditya Gupta
2025-10-21 13:48 ` [PATCH v5 7/8] tests/functional: Add test for fadump in PSeries Aditya Gupta
2025-10-21 13:48 ` [PATCH v5 8/8] MAINTAINERS: Add entry for FADump (pSeries) Aditya Gupta
2025-10-23  9:10   ` Sourabh Jain
2025-10-23  7:21 ` [PATCH v5 0/8] Implement Firmware Assisted Dump for PSeries shivang upadhyay
2025-10-23  7:35   ` Aditya Gupta

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20251021134823.1861675-6-adityag@linux.ibm.com \
    --to=adityag@linux.ibm.com \
    --cc=danielhb413@gmail.com \
    --cc=harshpb@linux.ibm.com \
    --cc=hbathini@linux.ibm.com \
    --cc=mahesh@linux.ibm.com \
    --cc=npiggin@gmail.com \
    --cc=philmd@linaro.org \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-ppc@nongnu.org \
    --cc=rathc@linux.ibm.com \
    --cc=shivangu@linux.ibm.com \
    --cc=sourabhjain@linux.ibm.com \
    --cc=thuth@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).