[PATCH v14 13/25] x86/xen/time: initialize pv xen time in init_hypervisor_platform

Pavel Tatashin
2018-07-18T02:21:59Z

In every hypervisor except for xen pv time ops are initialized in
init_hypervisor_platform().

Xen PV domains initialize time ops in x86_init.paging.pagetable_init(),
by calling xen_setup_shared_info() which is a poor design, as time is
needed prior to memory allocator.

xen_setup_shared_info() is called from two places: during boot, and
after suspend. Split the content of xen_setup_shared_info() into
three places:

1. add the clock relavent data into new xen pv init_platform vector, and
set clock ops in there.

2. move xen_setup_vcpu_info_placement() to new xen_pv_guest_late_init()
call.

3. Re-initializing parts of shared info copy to xen_pv_post_suspend() to
be symmetric to xen_pv_pre_suspend

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
---
arch/x86/xen/enlighten_pv.c | 51 +++++++++++++++++--------------------
arch/x86/xen/mmu_pv.c | 6 ++---
arch/x86/xen/suspend_pv.c | 5 ++--
arch/x86/xen/time.c | 7 +++--
arch/x86/xen/xen-ops.h | 6 ++---
5 files changed, 34 insertions(+), 41 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 439a94bf89ad..105a57d73701 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -119,6 +119,27 @@ static void __init xen_banner(void)
version >> 16, version & 0xffff, extra.extraversion,
xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
}
+
+static void __init xen_pv_init_platform(void)
+{
+ set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
+ HYPERVISOR_shared_info = (void *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
+
+ /* xen clock uses per-cpu vcpu_info, need to init it for boot cpu */
+ xen_vcpu_info_reset(0);
+
+ /* pvclock is in shared info area */
+ xen_init_time_ops();
+}
+
+static void __init xen_pv_guest_late_init(void)
+{
+#ifndef CONFIG_SMP
+ /* Setup shared vcpu info for non-smp configurations */
+ xen_setup_vcpu_info_placement();
+#endif
+}
+
/* Check if running on Xen version (major, minor) or later */
bool
xen_running_on_version_or_later(unsigned int major, unsigned int minor)
@@ -947,34 +968,8 @@ static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
xen_write_msr_safe(msr, low, high);
}

-void xen_setup_shared_info(void)
-{
- set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
-
- HYPERVISOR_shared_info =
- (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
-
- xen_setup_mfn_list_list();
-
- if (system_state == SYSTEM_BOOTING) {
-#ifndef CONFIG_SMP
- /*
- * In UP this is as good a place as any to set up shared info.
- * Limit this to boot only, at restore vcpu setup is done via
- * xen_vcpu_restore().
- */
- xen_setup_vcpu_info_placement();
-#endif
- /*
- * Now that shared info is set up we can start using routines
- * that point to pvclock area.
- */
- xen_init_time_ops();
- }
-}
-
/* This is called once we have the cpu_possible_mask */
-void __ref xen_setup_vcpu_info_placement(void)
+void __init xen_setup_vcpu_info_placement(void)
{
int cpu;

@@ -1228,6 +1223,8 @@ asmlinkage __visible void __init xen_start_kernel(void)
x86_init.irqs.intr_mode_init = x86_init_noop;
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;
+ x86_init.hyper.init_platform = xen_pv_init_platform;
+ x86_init.hyper.guest_late_init = xen_pv_guest_late_init;

/*
* Set up some pagetable state before starting to set any ptes.
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 2c30cabfda90..52206ad81e4b 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -1230,8 +1230,7 @@ static void __init xen_pagetable_p2m_free(void)
* We roundup to the PMD, which means that if anybody at this stage is
* using the __ka address of xen_start_info or
* xen_start_info->shared_info they are in going to crash. Fortunatly
- * we have already revectored in xen_setup_kernel_pagetable and in
- * xen_setup_shared_info.
+ * we have already revectored in xen_setup_kernel_pagetable.
*/
size = roundup(size, PMD_SIZE);

@@ -1292,8 +1291,7 @@ static void __init xen_pagetable_init(void)

/* Remap memory freed due to conflicts with E820 map */
xen_remap_memory();
-
- xen_setup_shared_info();
+ xen_setup_mfn_list_list();
}
static void xen_write_cr2(unsigned long cr2)
{
diff --git a/arch/x86/xen/suspend_pv.c b/arch/x86/xen/suspend_pv.c
index a2e0f110af56..8303b58c79a9 100644
--- a/arch/x86/xen/suspend_pv.c
+++ b/arch/x86/xen/suspend_pv.c
@@ -27,8 +27,9 @@ void xen_pv_pre_suspend(void)
void xen_pv_post_suspend(int suspend_cancelled)
{
xen_build_mfn_list_list();
-
- xen_setup_shared_info();
+ set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
+ HYPERVISOR_shared_info = (void *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
+ xen_setup_mfn_list_list();

if (suspend_cancelled) {
xen_start_info->store_mfn =
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index e0f1bcf01d63..53bb7a8d10b5 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -40,7 +40,7 @@ static unsigned long xen_tsc_khz(void)
return pvclock_tsc_khz(info);
}

-u64 xen_clocksource_read(void)
+static u64 xen_clocksource_read(void)
{
struct pvclock_vcpu_time_info *src;
u64 ret;
@@ -503,7 +503,7 @@ static void __init xen_time_init(void)
pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
}

-void __ref xen_init_time_ops(void)
+void __init xen_init_time_ops(void)
{
pv_time_ops = xen_time_ops;

@@ -542,8 +542,7 @@ void __init xen_hvm_init_time_ops(void)
return;

if (!xen_feature(XENFEAT_hvm_safe_pvclock)) {
- printk(KERN_INFO "Xen doesn't support pvclock on HVM,"
- "disable pv timer\n");
+ pr_info("Xen doesn't support pvclock on HVM, disable pv timer");
return;
}

diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 3b34745d0a52..e78684597f57 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -31,7 +31,6 @@ extern struct shared_info xen_dummy_shared_info;
extern struct shared_info *HYPERVISOR_shared_info;

void xen_setup_mfn_list_list(void);
-void xen_setup_shared_info(void);
void xen_build_mfn_list_list(void);
void xen_setup_machphys_mapping(void);
void xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
@@ -68,12 +67,11 @@ void xen_init_irq_ops(void);
void xen_setup_timer(int cpu);
void xen_setup_runstate_info(int cpu);
void xen_teardown_timer(int cpu);
-u64 xen_clocksource_read(void);
void xen_setup_cpu_clockevents(void);
void xen_save_time_memory_area(void);
void xen_restore_time_memory_area(void);
-void __ref xen_init_time_ops(void);
-void __init xen_hvm_init_time_ops(void);
+void xen_init_time_ops(void);
+void xen_hvm_init_time_ops(void);

irqreturn_t xen_debug_interrupt(int irq, void *dev_id);

--
2.18.0