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-rw-r--r--arch/x86/xen/enlighten.c339
1 files changed, 236 insertions, 103 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 750f46ad018a..53282dc7d5ac 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1,59 +1,47 @@
// SPDX-License-Identifier: GPL-2.0
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-#include <linux/memblock.h>
-#endif
+#include <linux/console.h>
#include <linux/cpu.h>
+#include <linux/instrumentation.h>
#include <linux/kexec.h>
+#include <linux/memblock.h>
#include <linux/slab.h>
+#include <linux/panic_notifier.h>
#include <xen/xen.h>
#include <xen/features.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/version.h>
#include <xen/page.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <asm/cpu.h>
#include <asm/e820/api.h>
+#include <asm/setup.h>
#include "xen-ops.h"
-#include "smp.h"
-#include "pmu.h"
-EXPORT_SYMBOL_GPL(hypercall_page);
+DEFINE_STATIC_CALL(xen_hypercall, xen_hypercall_hvm);
+EXPORT_STATIC_CALL_TRAMP(xen_hypercall);
/*
* Pointer to the xen_vcpu_info structure or
* &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
* and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
- * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point
- * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to
- * acknowledge pending events.
- * Also more subtly it is used by the patched version of irq enable/disable
- * e.g. xen_irq_enable_direct and xen_iret in PV mode.
- *
- * The desire to be able to do those mask/unmask operations as a single
- * instruction by using the per-cpu offset held in %gs is the real reason
- * vcpu info is in a per-cpu pointer and the original reason for this
- * hypercall.
- *
+ * but during boot it is switched to point to xen_vcpu_info.
+ * The pointer is used in xen_evtchn_do_upcall to acknowledge pending events.
+ * Make sure that xen_vcpu_info doesn't cross a page boundary by making it
+ * cache-line aligned (the struct is guaranteed to have a size of 64 bytes,
+ * which matches the cache line size of 64-bit x86 processors).
*/
DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
-
-/*
- * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info
- * hypercall. This can be used both in PV and PVHVM mode. The structure
- * overrides the default per_cpu(xen_vcpu, cpu) value.
- */
-DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
+DEFINE_PER_CPU_ALIGNED(struct vcpu_info, xen_vcpu_info);
/* Linux <-> Xen vCPU id mapping */
DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
-enum xen_domain_type xen_domain_type = XEN_NATIVE;
-EXPORT_SYMBOL_GPL(xen_domain_type);
-
unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
EXPORT_SYMBOL(machine_to_phys_mapping);
unsigned long machine_to_phys_nr;
@@ -64,14 +52,16 @@ EXPORT_SYMBOL_GPL(xen_start_info);
struct shared_info xen_dummy_shared_info;
-__read_mostly int xen_have_vector_callback;
+__read_mostly bool xen_have_vector_callback = true;
EXPORT_SYMBOL_GPL(xen_have_vector_callback);
/*
- * NB: needs to live in .data because it's used by xen_prepare_pvh which runs
- * before clearing the bss.
+ * NB: These need to live in .data or alike because they're used by
+ * xen_prepare_pvh() which runs before clearing the bss.
*/
-uint32_t xen_start_flags __attribute__((section(".data"))) = 0;
+enum xen_domain_type __ro_after_init xen_domain_type = XEN_NATIVE;
+EXPORT_SYMBOL_GPL(xen_domain_type);
+uint32_t __ro_after_init xen_start_flags;
EXPORT_SYMBOL(xen_start_flags);
/*
@@ -80,20 +70,64 @@ EXPORT_SYMBOL(xen_start_flags);
*/
struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
+/* Number of pages released from the initial allocation. */
+unsigned long xen_released_pages;
+
+static __ref void xen_get_vendor(void)
+{
+ init_cpu_devs();
+ cpu_detect(&boot_cpu_data);
+ get_cpu_vendor(&boot_cpu_data);
+}
+
+void xen_hypercall_setfunc(void)
+{
+ if (static_call_query(xen_hypercall) != xen_hypercall_hvm)
+ return;
+
+ if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
+ static_call_update(xen_hypercall, xen_hypercall_amd);
+ else
+ static_call_update(xen_hypercall, xen_hypercall_intel);
+}
+
/*
- * Flag to determine whether vcpu info placement is available on all
- * VCPUs. We assume it is to start with, and then set it to zero on
- * the first failure. This is because it can succeed on some VCPUs
- * and not others, since it can involve hypervisor memory allocation,
- * or because the guest failed to guarantee all the appropriate
- * constraints on all VCPUs (ie buffer can't cross a page boundary).
- *
- * Note that any particular CPU may be using a placed vcpu structure,
- * but we can only optimise if the all are.
- *
- * 0: not available, 1: available
+ * Evaluate processor vendor in order to select the correct hypercall
+ * function for HVM/PVH guests.
+ * Might be called very early in boot before vendor has been set by
+ * early_cpu_init().
*/
-int xen_have_vcpu_info_placement = 1;
+noinstr void *__xen_hypercall_setfunc(void)
+{
+ void (*func)(void);
+
+ /*
+ * Note that __xen_hypercall_setfunc() is noinstr only due to a nasty
+ * dependency chain: it is being called via the xen_hypercall static
+ * call when running as a PVH or HVM guest. Hypercalls need to be
+ * noinstr due to PV guests using hypercalls in noinstr code. So we
+ * can safely tag the function body as "instrumentation ok", since
+ * the PV guest requirement is not of interest here (xen_get_vendor()
+ * calls noinstr functions, and static_call_update_early() might do
+ * so, too).
+ */
+ instrumentation_begin();
+
+ xen_get_vendor();
+
+ if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
+ func = xen_hypercall_amd;
+ else
+ func = xen_hypercall_intel;
+
+ static_call_update_early(xen_hypercall, func);
+
+ instrumentation_end();
+
+ return func;
+}
static int xen_cpu_up_online(unsigned int cpu)
{
@@ -120,10 +154,8 @@ int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int),
return rc >= 0 ? 0 : rc;
}
-static int xen_vcpu_setup_restore(int cpu)
+static void xen_vcpu_setup_restore(int cpu)
{
- int rc = 0;
-
/* Any per_cpu(xen_vcpu) is stale, so reset it */
xen_vcpu_info_reset(cpu);
@@ -132,11 +164,8 @@ static int xen_vcpu_setup_restore(int cpu)
* be handled by hotplug.
*/
if (xen_pv_domain() ||
- (xen_hvm_domain() && cpu_online(cpu))) {
- rc = xen_vcpu_setup(cpu);
- }
-
- return rc;
+ (xen_hvm_domain() && cpu_online(cpu)))
+ xen_vcpu_setup(cpu);
}
/*
@@ -146,7 +175,7 @@ static int xen_vcpu_setup_restore(int cpu)
*/
void xen_vcpu_restore(void)
{
- int cpu, rc;
+ int cpu;
for_each_possible_cpu(cpu) {
bool other_cpu = (cpu != smp_processor_id());
@@ -166,20 +195,9 @@ void xen_vcpu_restore(void)
if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
xen_setup_runstate_info(cpu);
- rc = xen_vcpu_setup_restore(cpu);
- if (rc)
- pr_emerg_once("vcpu restore failed for cpu=%d err=%d. "
- "System will hang.\n", cpu, rc);
- /*
- * In case xen_vcpu_setup_restore() fails, do not bring up the
- * VCPU. This helps us avoid the resulting OOPS when the VCPU
- * accesses pvclock_vcpu_time via xen_vcpu (which is NULL.)
- * Note that this does not improve the situation much -- now the
- * VM hangs instead of OOPSing -- with the VCPUs that did not
- * fail, spinning in stop_machine(), waiting for the failed
- * VCPUs to come up.
- */
- if (other_cpu && is_up && (rc == 0) &&
+ xen_vcpu_setup_restore(cpu);
+
+ if (other_cpu && is_up &&
HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
BUG();
}
@@ -196,12 +214,13 @@ void xen_vcpu_info_reset(int cpu)
}
}
-int xen_vcpu_setup(int cpu)
+void xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
int err;
struct vcpu_info *vcpup;
+ BUILD_BUG_ON(sizeof(*vcpup) > SMP_CACHE_BYTES);
BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
/*
@@ -217,44 +236,65 @@ int xen_vcpu_setup(int cpu)
*/
if (xen_hvm_domain()) {
if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
- return 0;
+ return;
}
- if (xen_have_vcpu_info_placement) {
- vcpup = &per_cpu(xen_vcpu_info, cpu);
- info.mfn = arbitrary_virt_to_mfn(vcpup);
- info.offset = offset_in_page(vcpup);
+ vcpup = &per_cpu(xen_vcpu_info, cpu);
+ info.mfn = arbitrary_virt_to_mfn(vcpup);
+ info.offset = offset_in_page(vcpup);
- /*
- * Check to see if the hypervisor will put the vcpu_info
- * structure where we want it, which allows direct access via
- * a percpu-variable.
- * N.B. This hypercall can _only_ be called once per CPU.
- * Subsequent calls will error out with -EINVAL. This is due to
- * the fact that hypervisor has no unregister variant and this
- * hypercall does not allow to over-write info.mfn and
- * info.offset.
- */
- err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info,
- xen_vcpu_nr(cpu), &info);
-
- if (err) {
- pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n",
- cpu, err);
- xen_have_vcpu_info_placement = 0;
- } else {
- /*
- * This cpu is using the registered vcpu info, even if
- * later ones fail to.
- */
- per_cpu(xen_vcpu, cpu) = vcpup;
- }
- }
+ /*
+ * N.B. This hypercall can _only_ be called once per CPU.
+ * Subsequent calls will error out with -EINVAL. This is due to
+ * the fact that hypervisor has no unregister variant and this
+ * hypercall does not allow to over-write info.mfn and
+ * info.offset.
+ */
+ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
+ &info);
+ if (err)
+ panic("register_vcpu_info failed: cpu=%d err=%d\n", cpu, err);
+
+ per_cpu(xen_vcpu, cpu) = vcpup;
+}
+
+void __init xen_banner(void)
+{
+ unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
+ struct xen_extraversion extra;
- if (!xen_have_vcpu_info_placement)
- xen_vcpu_info_reset(cpu);
+ HYPERVISOR_xen_version(XENVER_extraversion, &extra);
- return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0);
+ pr_info("Booting kernel on %s\n", pv_info.name);
+ pr_info("Xen version: %u.%u%s%s\n",
+ version >> 16, version & 0xffff, extra.extraversion,
+ xen_feature(XENFEAT_mmu_pt_update_preserve_ad)
+ ? " (preserve-AD)" : "");
+}
+
+/* Check if running on Xen version (major, minor) or later */
+bool xen_running_on_version_or_later(unsigned int major, unsigned int minor)
+{
+ unsigned int version;
+
+ if (!xen_domain())
+ return false;
+
+ version = HYPERVISOR_xen_version(XENVER_version, NULL);
+ if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
+ ((version >> 16) > major))
+ return true;
+ return false;
+}
+
+void __init xen_add_preferred_consoles(void)
+{
+ add_preferred_console("xenboot", 0, NULL);
+ if (!boot_params.screen_info.orig_video_isVGA)
+ add_preferred_console("tty", 0, NULL);
+ add_preferred_console("hvc", 0, NULL);
+ if (boot_params.screen_info.orig_video_isVGA)
+ add_preferred_console("tty", 0, NULL);
}
void xen_reboot(int reason)
@@ -269,19 +309,41 @@ void xen_reboot(int reason)
BUG();
}
+static int reboot_reason = SHUTDOWN_reboot;
+static bool xen_legacy_crash;
void xen_emergency_restart(void)
{
- xen_reboot(SHUTDOWN_reboot);
+ xen_reboot(reboot_reason);
}
static int
xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
{
- if (!kexec_crash_loaded())
- xen_reboot(SHUTDOWN_crash);
+ if (!kexec_crash_loaded()) {
+ if (xen_legacy_crash)
+ xen_reboot(SHUTDOWN_crash);
+
+ reboot_reason = SHUTDOWN_crash;
+
+ /*
+ * If panic_timeout==0 then we are supposed to wait forever.
+ * However, to preserve original dom0 behavior we have to drop
+ * into hypervisor. (domU behavior is controlled by its
+ * config file)
+ */
+ if (panic_timeout == 0)
+ panic_timeout = -1;
+ }
return NOTIFY_DONE;
}
+static int __init parse_xen_legacy_crash(char *arg)
+{
+ xen_legacy_crash = true;
+ return 0;
+}
+early_param("xen_legacy_crash", parse_xen_legacy_crash);
+
static struct notifier_block xen_panic_block = {
.notifier_call = xen_panic_event,
.priority = INT_MIN
@@ -345,3 +407,74 @@ void xen_arch_unregister_cpu(int num)
}
EXPORT_SYMBOL(xen_arch_unregister_cpu);
#endif
+
+/* Amount of extra memory space we add to the e820 ranges */
+struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
+
+void __init xen_add_extra_mem(unsigned long start_pfn, unsigned long n_pfns)
+{
+ unsigned int i;
+
+ /*
+ * No need to check for zero size, should happen rarely and will only
+ * write a new entry regarded to be unused due to zero size.
+ */
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ /* Add new region. */
+ if (xen_extra_mem[i].n_pfns == 0) {
+ xen_extra_mem[i].start_pfn = start_pfn;
+ xen_extra_mem[i].n_pfns = n_pfns;
+ break;
+ }
+ /* Append to existing region. */
+ if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
+ start_pfn) {
+ xen_extra_mem[i].n_pfns += n_pfns;
+ break;
+ }
+ }
+ if (i == XEN_EXTRA_MEM_MAX_REGIONS)
+ printk(KERN_WARNING "Warning: not enough extra memory regions\n");
+
+ memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
+}
+
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
+int __init arch_xen_unpopulated_init(struct resource **res)
+{
+ unsigned int i;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ /* Must be set strictly before calling xen_free_unpopulated_pages(). */
+ *res = &iomem_resource;
+
+ /*
+ * Initialize with pages from the extra memory regions (see
+ * arch/x86/xen/setup.c).
+ */
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ unsigned int j;
+
+ for (j = 0; j < xen_extra_mem[i].n_pfns; j++) {
+ struct page *pg =
+ pfn_to_page(xen_extra_mem[i].start_pfn + j);
+
+ xen_free_unpopulated_pages(1, &pg);
+ }
+
+ /*
+ * Account for the region being in the physmap but unpopulated.
+ * The value in xen_released_pages is used by the balloon
+ * driver to know how much of the physmap is unpopulated and
+ * set an accurate initial memory target.
+ */
+ xen_released_pages += xen_extra_mem[i].n_pfns;
+ /* Zero so region is not also added to the balloon driver. */
+ xen_extra_mem[i].n_pfns = 0;
+ }
+
+ return 0;
+}
+#endif
generated by cgit (git 2.34.1) at 2025-12-24 23:30:59 +0000