Attachment 252140 Details for Bug 277200 – Fix candidate for 14

[patch] Fix candidate for 14

0001-xen-pvh-fix-initialization-of-environment.patch (text/plain), 5.56 KB, created by Roger Pau Monné on 2024-07-18 09:47:35 UTC

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Creator: Roger Pau Monné

Created: 2024-07-18 09:47:35 UTC

Size: 5.56 KB

patch

obsolete

>From 591311d36d619051e78ad2780d42fce2d94ef8ff Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <royger@FreeBSD.org>
>Date: Thu, 18 Jul 2024 11:44:17 +0200
>Subject: [PATCH] xen/pvh: fix initialization of environment
>
>Xen PVH entry point requires to modify the environment passed from the boot
>loader, so that the ACPI RSDP is re-written to use the Xen generated RSDP
>instead of the native one.
>
>The current logic in the PVH entry point reserves a single page (4K) in order
>to copy the contents of the environment passed from the boot loader, so that
>the bootloader provided "acpi.rsdp" is dropped and a Xen specific one is added
>afterwards.
>
>This however doesn't scale well, as it's possible for the environment to be
>bigger than 4K.  Bumping the buffer, or attempting to peek at the size of the
>metadata all seem to just add more complexity to a sensitive path.  Instead
>introduce a new ACPI hook that allows setting the RSDP address directly, and
>use it from the PVH entry point so set the position of the Xen generated RSDP.
>
>This allows to reduce the logic in the PVH metadata processing, as there's no
>need to parse and filter the bootloader provided environment.
>
>Sponsored by: Cloud Software Group
>PR: 277200
>---
> sys/x86/acpica/OsdEnvironment.c  |  8 ++++
> sys/x86/include/acpica_machdep.h |  2 +
> sys/x86/xen/pv.c                 | 68 +++-----------------------------
> 3 files changed, 15 insertions(+), 63 deletions(-)
>
>diff --git a/sys/x86/acpica/OsdEnvironment.c b/sys/x86/acpica/OsdEnvironment.c
>index 6d6448fbcf0f..3f3b0448b35d 100644
>--- a/sys/x86/acpica/OsdEnvironment.c
>+++ b/sys/x86/acpica/OsdEnvironment.c
>@@ -78,6 +78,14 @@ acpi_get_root_from_memory(void)
> 	return (0);
> }
> 
>+void
>+acpi_set_root(vm_paddr_t addr)
>+{
>+
>+    KASSERT(acpi_root_phys == 0, ("ACPI root pointer already set"));
>+    acpi_root_phys = addr;
>+}
>+
> ACPI_PHYSICAL_ADDRESS
> AcpiOsGetRootPointer(void)
> {
>diff --git a/sys/x86/include/acpica_machdep.h b/sys/x86/include/acpica_machdep.h
>index b4811e4bd30c..2592b47ae1c1 100644
>--- a/sys/x86/include/acpica_machdep.h
>+++ b/sys/x86/include/acpica_machdep.h
>@@ -84,6 +84,8 @@ void	madt_parse_interrupt_values(void *entry,
> extern int madt_found_sci_override;
> extern int (*apei_nmi)(void);
> 
>+void	acpi_set_root(vm_paddr_t addr);
>+
> #endif /* _KERNEL */
> 
> #endif /* __ACPICA_MACHDEP_H__ */
>diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
>index c9537d153820..f19f93bfcb75 100644
>--- a/sys/x86/xen/pv.c
>+++ b/sys/x86/xen/pv.c
>@@ -60,6 +60,7 @@
> 
> #include <machine/_inttypes.h>
> #include <machine/intr_machdep.h>
>+#include <x86/acpica_machdep.h>
> #include <x86/apicvar.h>
> #include <x86/init.h>
> #include <machine/pc/bios.h>
>@@ -161,7 +162,6 @@ hammer_time_xen(vm_paddr_t start_info_paddr)
> 	struct hvm_modlist_entry *mod;
> 	struct xen_add_to_physmap xatp;
> 	uint64_t physfree;
>-	char *kenv;
> 	int rc;
> 
> 	if (isxen()) {
>@@ -225,15 +225,6 @@ hammer_time_xen(vm_paddr_t start_info_paddr)
> 		physfree += PAGE_SIZE;
> 	}
> 
>-	/*
>-	 * Init a static kenv using a free page. The contents will be filled
>-	 * from the parse_preload_data hook.
>-	 */
>-	kenv = (void *)(physfree + KERNBASE);
>-	physfree += PAGE_SIZE;
>-	bzero_early(kenv, PAGE_SIZE);
>-	init_static_kenv(kenv, PAGE_SIZE);
>-
> 	/* Set the hooks for early functions that diverge from bare metal */
> 	init_ops = xen_pvh_init_ops;
> 	hvm_start_flags = start_info->flags;
>@@ -244,52 +235,6 @@ hammer_time_xen(vm_paddr_t start_info_paddr)
> 
> /*-------------------------------- PV specific -------------------------------*/
> 
>-/*
>- * When booted as a PVH guest FreeBSD needs to avoid using the RSDP address
>- * hint provided by the loader because it points to the native set of ACPI
>- * tables instead of the ones crafted by Xen. The acpi.rsdp env variable is
>- * removed from kenv if present, and a new acpi.rsdp is added to kenv that
>- * points to the address of the Xen crafted RSDP.
>- */
>-static bool reject_option(const char *option)
>-{
>-	static const char *reject[] = {
>-		"acpi.rsdp",
>-	};
>-	unsigned int i;
>-
>-	for (i = 0; i < nitems(reject); i++)
>-		if (strncmp(option, reject[i], strlen(reject[i])) == 0)
>-			return (true);
>-
>-	return (false);
>-}
>-
>-static void
>-xen_pvh_set_env(char *env, bool (*filter)(const char *))
>-{
>-	char *option;
>-
>-	if (env == NULL)
>-		return;
>-
>-	option = env;
>-	while (*option != 0) {
>-		char *value;
>-
>-		if (filter != NULL && filter(option)) {
>-			option += strlen(option) + 1;
>-			continue;
>-		}
>-
>-		value = option;
>-		option = strsep(&value, "=");
>-		if (kern_setenv(option, value) != 0 && isxen())
>-			xc_printf("unable to add kenv %s=%s\n", option, value);
>-		option = value + strlen(value) + 1;
>-	}
>-}
>-
> #ifdef DDB
> /*
>  * The way Xen loads the symtab is different from the native boot loader,
>@@ -414,7 +359,6 @@ xen_pvh_parse_preload_data(uint64_t modulep)
> 	vm_ooffset_t off;
> 	vm_paddr_t metadata;
> 	char *envp;
>-	char acpi_rsdp[19];
> 
> 	TSENTER();
> 	if (start_info->modlist_paddr != 0) {
>@@ -478,9 +422,9 @@ xen_pvh_parse_preload_data(uint64_t modulep)
> 
> 		boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
> 		envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *);
>-		if (envp != NULL)
>-			envp += off;
>-		xen_pvh_set_env(envp, reject_option);
>+		if ( envp != NULL )
>+		    envp += off;
>+		init_static_kenv(envp, 0);
> 
> 		if (MD_FETCH(kmdp, MODINFOMD_EFI_MAP, void *) != NULL)
> 		    strlcpy(bootmethod, "UEFI", sizeof(bootmethod));
>@@ -500,9 +444,7 @@ xen_pvh_parse_preload_data(uint64_t modulep)
> 
> 	boothowto |= boot_env_to_howto();
> 
>-	snprintf(acpi_rsdp, sizeof(acpi_rsdp), "%#" PRIx64,
>-	    start_info->rsdp_paddr);
>-	kern_setenv("acpi.rsdp", acpi_rsdp);
>+	acpi_set_root(start_info->rsdp_paddr);
> 
> #ifdef DDB
> 	xen_pvh_parse_symtab();
>-- 
>2.45.2
>

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Attachments on bug 277200: 248646 | 248661 | 252140