[PATCH 2/3] xen/x86: bzImage parse kernel_alignment

From: Jason Andryuk <jason.andryuk@amd.com>
To: <xen-devel@lists.xenproject.org>
Cc: "Jason Andryuk" <jason.andryuk@amd.com>,
	"Jan Beulich" <jbeulich@suse.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>
Subject: [PATCH 2/3] xen/x86: bzImage parse kernel_alignment
Date: Wed, 6 Mar 2024 13:50:31 -0500	[thread overview]
Message-ID: <20240306185032.103216-3-jason.andryuk@amd.com> (raw)
In-Reply-To: <20240306185032.103216-1-jason.andryuk@amd.com>

Expand bzimage_parse() to return kernel_alignment from the setup_header.
This will be needed if loading a PVH kernel at a physical offset to
compensate for a reserved E820 region.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
 xen/arch/x86/bzimage.c             | 4 +++-
 xen/arch/x86/hvm/dom0_build.c      | 4 +++-
 xen/arch/x86/include/asm/bzimage.h | 3 +--
 xen/arch/x86/pv/dom0_build.c       | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/bzimage.c b/xen/arch/x86/bzimage.c
index ac4fd428be..0f4cfc49f7 100644
--- a/xen/arch/x86/bzimage.c
+++ b/xen/arch/x86/bzimage.c
@@ -105,7 +105,7 @@ unsigned long __init bzimage_headroom(void *image_start,
 }
 
 int __init bzimage_parse(void *image_base, void **image_start,
-                         unsigned long *image_len)
+                         unsigned long *image_len, unsigned int *align)
 {
     struct setup_header *hdr = (struct setup_header *)(*image_start);
     int err = bzimage_check(hdr, *image_len);
@@ -118,6 +118,8 @@ int __init bzimage_parse(void *image_base, void **image_start,
     {
         *image_start += (hdr->setup_sects + 1) * 512 + hdr->payload_offset;
         *image_len = hdr->payload_length;
+        if ( align )
+            *align = hdr->kernel_alignment;
     }
 
     if ( elf_is_elfbinary(*image_start, *image_len) )
diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index 0ceda4140b..bbae8a5645 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -548,12 +548,14 @@ static int __init pvh_load_kernel(struct domain *d, const module_t *image,
     struct elf_binary elf;
     struct elf_dom_parms parms;
     paddr_t last_addr;
+    unsigned int align = 0;
     struct hvm_start_info start_info = { 0 };
     struct hvm_modlist_entry mod = { 0 };
     struct vcpu *v = d->vcpu[0];
     int rc;
 
-    if ( (rc = bzimage_parse(image_base, &image_start, &image_len)) != 0 )
+    rc = bzimage_parse(image_base, &image_start, &image_len, &align);
+    if ( rc != 0 )
     {
         printk("Error trying to detect bz compressed kernel\n");
         return rc;
diff --git a/xen/arch/x86/include/asm/bzimage.h b/xen/arch/x86/include/asm/bzimage.h
index 7ed69d3910..de4e9a446f 100644
--- a/xen/arch/x86/include/asm/bzimage.h
+++ b/xen/arch/x86/include/asm/bzimage.h
@@ -4,8 +4,7 @@
 #include <xen/init.h>
 
 unsigned long bzimage_headroom(void *image_start, unsigned long image_length);
-
 int bzimage_parse(void *image_base, void **image_start,
-                  unsigned long *image_len);
+                  unsigned long *image_len, unsigned int *align);
 
 #endif /* __X86_BZIMAGE_H__ */
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index d8043fa58a..e9fa8a9a82 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -416,7 +416,7 @@ int __init dom0_construct_pv(struct domain *d,
 
     d->max_pages = ~0U;
 
-    if ( (rc = bzimage_parse(image_base, &image_start, &image_len)) != 0 )
+    if ( (rc = bzimage_parse(image_base, &image_start, &image_len, NULL)) != 0 )
         return rc;
 
     if ( (rc = elf_init(&elf, image_start, image_len)) != 0 )
-- 
2.44.0


