[PATCH 0/2] Stable-6.6 backport x86/xen: fix memblock_reserve() usage on PVH

[PATCH 0/2] Stable-6.6 backport x86/xen: fix memblock_reserve() usage on PVH

[Jason Andryuk]

For stable-6.6.  

("x86/xen: fix memblock_reserve() usage on PVH") is the fix, but it
depends on ("x86/xen: move xen_reserve_extra_memory()") as a
prerequisite.  Both need fixups as they predate the removal of the Xen
hypercall_page.

Roger Pau Monne (2):
  x86/xen: move xen_reserve_extra_memory()
  x86/xen: fix memblock_reserve() usage on PVH

 arch/x86/include/asm/xen/hypervisor.h |  5 --
 arch/x86/platform/pvh/enlighten.c     |  3 -
 arch/x86/xen/enlighten_pvh.c          | 93 +++++++++++++++------------
 3 files changed, 51 insertions(+), 50 deletions(-)

-- 
2.49.0

[PATCH 1/2] x86/xen: move xen_reserve_extra_memory()

[Jason Andryuk]

From: Roger Pau Monne <roger.pau@citrix.com>

commit fc05ea89c9ab45e70cb73e70bc0b9cdd403e0ee1 upstream

In preparation for making the function static.

No functional change.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20240725073116.14626-2-roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
[ Stable backport - move the code as it exists ]
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
For stable-6.6

This patch is code movement, but it doesn't directly apply since it
predates the removal of the Xen hypercall_page.  This version moves
the code as it exists in 6.6.

Pre-req for 4c006734898a113a64a528027274a571b04af95a backport
---
 arch/x86/xen/enlighten_pvh.c | 82 ++++++++++++++++++------------------
 1 file changed, 41 insertions(+), 41 deletions(-)

diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index 60b358c2f434..89984018141c 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -26,47 +26,6 @@
 bool __ro_after_init xen_pvh;
 EXPORT_SYMBOL_GPL(xen_pvh);
 
-void __init xen_pvh_init(struct boot_params *boot_params)
-{
-	xen_pvh = 1;
-	xen_domain_type = XEN_HVM_DOMAIN;
-	xen_start_flags = pvh_start_info.flags;
-
-	if (xen_initial_domain())
-		x86_init.oem.arch_setup = xen_add_preferred_consoles;
-	x86_init.oem.banner = xen_banner;
-
-	xen_efi_init(boot_params);
-
-	if (xen_initial_domain()) {
-		struct xen_platform_op op = {
-			.cmd = XENPF_get_dom0_console,
-		};
-		int ret = HYPERVISOR_platform_op(&op);
-
-		if (ret > 0)
-			xen_init_vga(&op.u.dom0_console,
-				     min(ret * sizeof(char),
-					 sizeof(op.u.dom0_console)),
-				     &boot_params->screen_info);
-	}
-}
-
-void __init mem_map_via_hcall(struct boot_params *boot_params_p)
-{
-	struct xen_memory_map memmap;
-	int rc;
-
-	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
-	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
-	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
-	if (rc) {
-		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
-		BUG();
-	}
-	boot_params_p->e820_entries = memmap.nr_entries;
-}
-
 /*
  * Reserve e820 UNUSABLE regions to inflate the memory balloon.
  *
@@ -133,3 +92,44 @@ void __init xen_reserve_extra_memory(struct boot_params *bootp)
 		xen_add_extra_mem(PFN_UP(e->addr), pages);
 	}
 }
+
+void __init xen_pvh_init(struct boot_params *boot_params)
+{
+	xen_pvh = 1;
+	xen_domain_type = XEN_HVM_DOMAIN;
+	xen_start_flags = pvh_start_info.flags;
+
+	if (xen_initial_domain())
+		x86_init.oem.arch_setup = xen_add_preferred_consoles;
+	x86_init.oem.banner = xen_banner;
+
+	xen_efi_init(boot_params);
+
+	if (xen_initial_domain()) {
+		struct xen_platform_op op = {
+			.cmd = XENPF_get_dom0_console,
+		};
+		int ret = HYPERVISOR_platform_op(&op);
+
+		if (ret > 0)
+			xen_init_vga(&op.u.dom0_console,
+				     min(ret * sizeof(char),
+					 sizeof(op.u.dom0_console)),
+				     &boot_params->screen_info);
+	}
+}
+
+void __init mem_map_via_hcall(struct boot_params *boot_params_p)
+{
+	struct xen_memory_map memmap;
+	int rc;
+
+	memmap.nr_entries = ARRAY_SIZE(boot_params_p->e820_table);
+	set_xen_guest_handle(memmap.buffer, boot_params_p->e820_table);
+	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+	if (rc) {
+		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
+		BUG();
+	}
+	boot_params_p->e820_entries = memmap.nr_entries;
+}
-- 
2.49.0

[PATCH 2/2] x86/xen: fix memblock_reserve() usage on PVH

[Jason Andryuk]

From: Roger Pau Monne <roger.pau@citrix.com>

commit 4c006734898a113a64a528027274a571b04af95a upstream

The current usage of memblock_reserve() in init_pvh_bootparams() is done before
the .bss is zeroed, and that used to be fine when
memblock_reserved_init_regions implicitly ended up in the .meminit.data
section.  However after commit 73db3abdca58c memblock_reserved_init_regions
ends up in the .bss section, thus breaking it's usage before the .bss is
cleared.

Move and rename the call to xen_reserve_extra_memory() so it's done in the
x86_init.oem.arch_setup hook, which gets executed after the .bss has been
zeroed, but before calling e820__memory_setup().

Fixes: 73db3abdca58c ("init/modpost: conditionally check section mismatch to __meminit*")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20240725073116.14626-3-roger.pau@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
[ Context fixup for hypercall_page removal ]
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
---
For stable-6.6

Context fixup is needed to cherry-pick after Xen hypercall_page removal.

The Fixes commit was backported to 6.6, so this is needed to fix booting
for Xen PVH.
---
 arch/x86/include/asm/xen/hypervisor.h |  5 -----
 arch/x86/platform/pvh/enlighten.c     |  3 ---
 arch/x86/xen/enlighten_pvh.c          | 15 ++++++++++++---
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index 64fbd2dbc5b7..a9088250770f 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -62,11 +62,6 @@ void xen_arch_unregister_cpu(int num);
 #ifdef CONFIG_PVH
 void __init xen_pvh_init(struct boot_params *boot_params);
 void __init mem_map_via_hcall(struct boot_params *boot_params_p);
-#ifdef CONFIG_XEN_PVH
-void __init xen_reserve_extra_memory(struct boot_params *bootp);
-#else
-static inline void xen_reserve_extra_memory(struct boot_params *bootp) { }
-#endif
 #endif
 
 /* Lazy mode for batching updates / context switch */
diff --git a/arch/x86/platform/pvh/enlighten.c b/arch/x86/platform/pvh/enlighten.c
index a12117f3d4de..00a92cb2c814 100644
--- a/arch/x86/platform/pvh/enlighten.c
+++ b/arch/x86/platform/pvh/enlighten.c
@@ -74,9 +74,6 @@ static void __init init_pvh_bootparams(bool xen_guest)
 	} else
 		xen_raw_printk("Warning: Can fit ISA range into e820\n");
 
-	if (xen_guest)
-		xen_reserve_extra_memory(&pvh_bootparams);
-
 	pvh_bootparams.hdr.cmd_line_ptr =
 		pvh_start_info.cmdline_paddr;
 
diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index 89984018141c..ac0a8adb2c50 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -8,6 +8,7 @@
 #include <asm/io_apic.h>
 #include <asm/hypervisor.h>
 #include <asm/e820/api.h>
+#include <asm/setup.h>
 
 #include <xen/xen.h>
 #include <asm/xen/interface.h>
@@ -40,8 +41,9 @@ EXPORT_SYMBOL_GPL(xen_pvh);
  * hypervisor should notify us which memory ranges are suitable for creating
  * foreign mappings, but that's not yet implemented.
  */
-void __init xen_reserve_extra_memory(struct boot_params *bootp)
+static void __init pvh_reserve_extra_memory(void)
 {
+	struct boot_params *bootp = &boot_params;
 	unsigned int i, ram_pages = 0, extra_pages;
 
 	for (i = 0; i < bootp->e820_entries; i++) {
@@ -93,14 +95,21 @@ void __init xen_reserve_extra_memory(struct boot_params *bootp)
 	}
 }
 
+static void __init pvh_arch_setup(void)
+{
+	pvh_reserve_extra_memory();
+
+	if (xen_initial_domain())
+		xen_add_preferred_consoles();
+}
+
 void __init xen_pvh_init(struct boot_params *boot_params)
 {
 	xen_pvh = 1;
 	xen_domain_type = XEN_HVM_DOMAIN;
 	xen_start_flags = pvh_start_info.flags;
 
-	if (xen_initial_domain())
-		x86_init.oem.arch_setup = xen_add_preferred_consoles;
+	x86_init.oem.arch_setup = pvh_arch_setup;
 	x86_init.oem.banner = xen_banner;
 
 	xen_efi_init(boot_params);
-- 
2.49.0

Re: [PATCH 2/2] x86/xen: fix memblock_reserve() usage on PVH

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 4c006734898a113a64a528027274a571b04af95a

WARNING: Author mismatch between patch and upstream commit:
Backport author: Jason Andryuk<jason.andryuk@amd.com>
Commit author: Roger Pau Monne<roger.pau@citrix.com>

Note: The patch differs from the upstream commit:
---
1:  4c006734898a1 < -:  ------------- x86/xen: fix memblock_reserve() usage on PVH
-:  ------------- > 1:  9bc5c94e278f7 Linux 6.14.2
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Success    |  Success   |

Re: [PATCH 1/2] x86/xen: move xen_reserve_extra_memory()

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: fc05ea89c9ab45e70cb73e70bc0b9cdd403e0ee1

WARNING: Author mismatch between patch and upstream commit:
Backport author: Jason Andryuk<jason.andryuk@amd.com>
Commit author: Roger Pau Monne<roger.pau@citrix.com>

Note: The patch differs from the upstream commit:
---
1:  fc05ea89c9ab4 < -:  ------------- x86/xen: move xen_reserve_extra_memory()
-:  ------------- > 1:  9bc5c94e278f7 Linux 6.14.2
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.4.y        |  Success    |  Success   |