From 36c7343b4ecac2432430f5393314f1bdc2c219a5 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 23 Jun 2008 12:06:52 +0100 Subject: tty_driver: Update required method documentation Some of the requirement rules are now more relaxed. Also correct a contradiction in the previous update Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/tty_driver.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index 59f1c0bd8f9c..d2a003586761 100644 --- a/include/linux/tty_driver.h +++ b/include/linux/tty_driver.h @@ -27,8 +27,7 @@ * This routine is called by the kernel to write a series of * characters to the tty device. The characters may come from * user space or kernel space. This routine will return the - * number of characters actually accepted for writing. This - * routine is mandatory. + * number of characters actually accepted for writing. * * Optional: Required for writable devices. * @@ -134,7 +133,7 @@ * This routine notifies the tty driver that it should hangup the * tty device. * - * Required: + * Optional: * * void (*break_ctl)(struct tty_stuct *tty, int state); * -- cgit v1.2.3 From 72c6e251ed84b3a9cdfde6711191155c47bb2b9c Mon Sep 17 00:00:00 2001 From: Thorsten Kranzkowski Date: Mon, 23 Jun 2008 20:57:22 +0000 Subject: alpha: fix compile error in arch/alpha/mm/init.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 9267b4b3880d00dc2dab90f1d817c856939114f7 ("alpha: fix module load failures on smp (bug #10926)") causes a regression for my ev4 uniprocessor build: CC arch/alpha/mm/init.o /export/data/repositories/linux-2.6/arch/alpha/mm/init.c:34: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘typeof’ make[2]: *** [arch/alpha/mm/init.o] Error 1 make[1]: *** [arch/alpha/mm] Error 2 make: *** [sub-make] Error 2 This fixes it for me (compile and boot tested): Signed-off-by: Thorsten Kranzkowski Acked-by: Ivan Kokshaysky Signed-off-by: Linus Torvalds --- include/asm-alpha/percpu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/asm-alpha/percpu.h b/include/asm-alpha/percpu.h index 82e8a94b4b2f..3495e8e00d70 100644 --- a/include/asm-alpha/percpu.h +++ b/include/asm-alpha/percpu.h @@ -69,6 +69,8 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; #define __get_cpu_var(var) per_cpu_var(var) #define __raw_get_cpu_var(var) per_cpu_var(var) +#define PER_CPU_ATTRIBUTES + #endif /* SMP */ #define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu_var(name) -- cgit v1.2.3 From 06e05645661211b9eaadaf6344c335d2e80f0ba2 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Fri, 6 Jun 2008 16:37:36 -0300 Subject: KVM: close timer injection race window in __vcpu_run If a timer fires after kvm_inject_pending_timer_irqs() but before local_irq_disable() the code will enter guest mode and only inject such timer interrupt the next time an unrelated event causes an exit. It would be simpler if the timer->pending irq conversion could be done with IRQ's disabled, so that the above problem cannot happen. For now introduce a new vcpu requests bit to cancel guest entry. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/i8254.c | 9 ++++++--- arch/x86/kvm/lapic.c | 1 + arch/x86/kvm/x86.c | 1 + include/linux/kvm_host.h | 1 + 4 files changed, 9 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index f2f5d260874e..3829aa7b663f 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -200,9 +200,12 @@ int __pit_timer_fn(struct kvm_kpit_state *ps) atomic_inc(&pt->pending); smp_mb__after_atomic_inc(); - if (vcpu0 && waitqueue_active(&vcpu0->wq)) { - vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE; - wake_up_interruptible(&vcpu0->wq); + if (vcpu0) { + set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests); + if (waitqueue_active(&vcpu0->wq)) { + vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE; + wake_up_interruptible(&vcpu0->wq); + } } pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period); diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c297c50eba63..ebc03f5ae162 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -940,6 +940,7 @@ static int __apic_timer_fn(struct kvm_lapic *apic) wait_queue_head_t *q = &apic->vcpu->wq; atomic_inc(&apic->timer.pending); + set_bit(KVM_REQ_PENDING_TIMER, &apic->vcpu->requests); if (waitqueue_active(q)) { apic->vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; wake_up_interruptible(q); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b90744a1dc3a..b08812d6b34c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2774,6 +2774,7 @@ again: } } + clear_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests); kvm_inject_pending_timer_irqs(vcpu); preempt_disable(); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 092b1b25291d..de9d1df4bba2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -33,6 +33,7 @@ #define KVM_REQ_REPORT_TPR_ACCESS 2 #define KVM_REQ_MMU_RELOAD 3 #define KVM_REQ_TRIPLE_FAULT 4 +#define KVM_REQ_PENDING_TIMER 5 struct kvm_vcpu; extern struct kmem_cache *kvm_vcpu_cache; -- cgit v1.2.3 From 28499143933f19b28008a556ed59255d6009391a Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 9 May 2008 12:05:57 +0100 Subject: xen: remove support for non-PAE 32-bit Non-PAE operation has been deprecated in Xen for a while, and is rarely tested or used. xen-unstable has now officially dropped non-PAE support. Since Xen/pvops' non-PAE support has also been broken for a while, we may as well completely drop it altogether. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/xen/Kconfig | 2 +- arch/x86/xen/enlighten.c | 51 ++++++++++++++++------------------------------ arch/x86/xen/mmu.c | 19 ++--------------- arch/x86/xen/mmu.h | 24 ++++++---------------- arch/x86/xen/xen-head.S | 4 ---- include/asm-x86/xen/page.h | 4 ---- 6 files changed, 27 insertions(+), 77 deletions(-) (limited to 'include') diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index 2e641be2737e..525b108411bd 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -6,7 +6,7 @@ config XEN bool "Xen guest support" select PARAVIRT depends on X86_32 - depends on X86_CMPXCHG && X86_TSC && !(X86_VISWS || X86_VOYAGER) + depends on X86_CMPXCHG && X86_TSC && X86_PAE && !(X86_VISWS || X86_VOYAGER) help This is the Linux Xen port. Enabling this will allow the kernel to boot in a paravirtualized environment under the diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index c048de34d6a1..f09c1c69c37a 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -785,38 +785,35 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte) static __init void xen_pagetable_setup_start(pgd_t *base) { pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base; + int i; /* special set_pte for pagetable initialization */ pv_mmu_ops.set_pte = xen_set_pte_init; init_mm.pgd = base; /* - * copy top-level of Xen-supplied pagetable into place. For - * !PAE we can use this as-is, but for PAE it is a stand-in - * while we copy the pmd pages. + * copy top-level of Xen-supplied pagetable into place. This + * is a stand-in while we copy the pmd pages. */ memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t)); - if (PTRS_PER_PMD > 1) { - int i; - /* - * For PAE, need to allocate new pmds, rather than - * share Xen's, since Xen doesn't like pmd's being - * shared between address spaces. - */ - for (i = 0; i < PTRS_PER_PGD; i++) { - if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) { - pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); + /* + * For PAE, need to allocate new pmds, rather than + * share Xen's, since Xen doesn't like pmd's being + * shared between address spaces. + */ + for (i = 0; i < PTRS_PER_PGD; i++) { + if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) { + pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); - memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]), - PAGE_SIZE); + memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]), + PAGE_SIZE); - make_lowmem_page_readonly(pmd); + make_lowmem_page_readonly(pmd); - set_pgd(&base[i], __pgd(1 + __pa(pmd))); - } else - pgd_clear(&base[i]); - } + set_pgd(&base[i], __pgd(1 + __pa(pmd))); + } else + pgd_clear(&base[i]); } /* make sure zero_page is mapped RO so we can use it in pagetables */ @@ -873,17 +870,7 @@ static __init void xen_pagetable_setup_done(pgd_t *base) /* Actually pin the pagetable down, but we can't set PG_pinned yet because the page structures don't exist yet. */ - { - unsigned level; - -#ifdef CONFIG_X86_PAE - level = MMUEXT_PIN_L3_TABLE; -#else - level = MMUEXT_PIN_L2_TABLE; -#endif - - pin_pagetable_pfn(level, PFN_DOWN(__pa(base))); - } + pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(base))); } /* This is called once we have the cpu_possible_map */ @@ -1093,7 +1080,6 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = { .make_pte = xen_make_pte, .make_pgd = xen_make_pgd, -#ifdef CONFIG_X86_PAE .set_pte_atomic = xen_set_pte_atomic, .set_pte_present = xen_set_pte_at, .set_pud = xen_set_pud, @@ -1102,7 +1088,6 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = { .make_pmd = xen_make_pmd, .pmd_val = xen_pmd_val, -#endif /* PAE */ .activate_mm = xen_activate_mm, .dup_mmap = xen_dup_mmap, diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 265601d5a6ae..df40bf74ea75 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -228,7 +228,7 @@ pmdval_t xen_pmd_val(pmd_t pmd) { return pte_mfn_to_pfn(pmd.pmd); } -#ifdef CONFIG_X86_PAE + void xen_set_pud(pud_t *ptr, pud_t val) { struct multicall_space mcs; @@ -276,12 +276,6 @@ pmd_t xen_make_pmd(pmdval_t pmd) pmd = pte_pfn_to_mfn(pmd); return native_make_pmd(pmd); } -#else /* !PAE */ -void xen_set_pte(pte_t *ptep, pte_t pte) -{ - *ptep = pte; -} -#endif /* CONFIG_X86_PAE */ /* (Yet another) pagetable walker. This one is intended for pinning a @@ -434,8 +428,6 @@ static int pin_page(struct page *page, enum pt_level level) read-only, and can be pinned. */ void xen_pgd_pin(pgd_t *pgd) { - unsigned level; - xen_mc_batch(); if (pgd_walk(pgd, pin_page, TASK_SIZE)) { @@ -445,14 +437,7 @@ void xen_pgd_pin(pgd_t *pgd) xen_mc_batch(); } -#ifdef CONFIG_X86_PAE - level = MMUEXT_PIN_L3_TABLE; -#else - level = MMUEXT_PIN_L2_TABLE; -#endif - - xen_do_pin(level, PFN_DOWN(__pa(pgd))); - + xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd))); xen_mc_issue(0); } diff --git a/arch/x86/xen/mmu.h b/arch/x86/xen/mmu.h index b5e189b1519d..5fe961caffd4 100644 --- a/arch/x86/xen/mmu.h +++ b/arch/x86/xen/mmu.h @@ -37,14 +37,13 @@ void xen_exit_mmap(struct mm_struct *mm); void xen_pgd_pin(pgd_t *pgd); //void xen_pgd_unpin(pgd_t *pgd); -#ifdef CONFIG_X86_PAE -unsigned long long xen_pte_val(pte_t); -unsigned long long xen_pmd_val(pmd_t); -unsigned long long xen_pgd_val(pgd_t); +pteval_t xen_pte_val(pte_t); +pmdval_t xen_pmd_val(pmd_t); +pgdval_t xen_pgd_val(pgd_t); -pte_t xen_make_pte(unsigned long long); -pmd_t xen_make_pmd(unsigned long long); -pgd_t xen_make_pgd(unsigned long long); +pte_t xen_make_pte(pteval_t); +pmd_t xen_make_pmd(pmdval_t); +pgd_t xen_make_pgd(pgdval_t); void xen_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval); @@ -53,15 +52,4 @@ void xen_set_pud(pud_t *ptr, pud_t val); void xen_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep); void xen_pmd_clear(pmd_t *pmdp); - -#else -unsigned long xen_pte_val(pte_t); -unsigned long xen_pmd_val(pmd_t); -unsigned long xen_pgd_val(pgd_t); - -pte_t xen_make_pte(unsigned long); -pmd_t xen_make_pmd(unsigned long); -pgd_t xen_make_pgd(unsigned long); -#endif - #endif /* _XEN_MMU_H */ diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S index 3175e973fd0d..6ec3b4f7719b 100644 --- a/arch/x86/xen/xen-head.S +++ b/arch/x86/xen/xen-head.S @@ -30,11 +30,7 @@ ENTRY(hypercall_page) ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, .long startup_xen) ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .long hypercall_page) ELFNOTE(Xen, XEN_ELFNOTE_FEATURES, .asciz "!writable_page_tables|pae_pgdir_above_4gb") -#ifdef CONFIG_X86_PAE ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes") -#else - ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "no") -#endif ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic") #endif /*CONFIG_XEN */ diff --git a/include/asm-x86/xen/page.h b/include/asm-x86/xen/page.h index baf3a4dce28c..e11f24038b1d 100644 --- a/include/asm-x86/xen/page.h +++ b/include/asm-x86/xen/page.h @@ -150,13 +150,9 @@ static inline pte_t __pte_ma(pteval_t x) return (pte_t) { .pte = x }; } -#ifdef CONFIG_X86_PAE #define pmd_val_ma(v) ((v).pmd) #define pud_val_ma(v) ((v).pgd.pgd) #define __pmd_ma(x) ((pmd_t) { (x) } ) -#else /* !X86_PAE */ -#define pmd_val_ma(v) ((v).pud.pgd.pgd) -#endif /* CONFIG_X86_PAE */ #define pgd_val_ma(x) ((x).pgd) -- cgit v1.2.3 From 7af192c954017499ec163bc9dbaaee2e593d7ef2 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 3 Jun 2008 16:17:29 +0200 Subject: x86: Add structs and functions for paravirt clocksource This patch adds structs for the paravirt clocksource ABI used by both xen and kvm (pvclock-abi.h). It also adds some helper functions to read system time and wall clock time from a paravirtual clocksource (pvclock.[ch]). They are based on the xen code. They are enabled using CONFIG_PARAVIRT_CLOCK. Subsequent patches of this series will put the code in use. Signed-off-by: Gerd Hoffmann Acked-by: Jeremy Fitzhardinge Signed-off-by: Avi Kivity --- arch/x86/Kconfig | 4 ++ arch/x86/kernel/Makefile | 1 + arch/x86/kernel/pvclock.c | 141 ++++++++++++++++++++++++++++++++++++++++++ include/asm-x86/pvclock-abi.h | 42 +++++++++++++ include/asm-x86/pvclock.h | 13 ++++ 5 files changed, 201 insertions(+) create mode 100644 arch/x86/kernel/pvclock.c create mode 100644 include/asm-x86/pvclock-abi.h create mode 100644 include/asm-x86/pvclock.h (limited to 'include') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 52e18e6d2ba0..f94bca6ff47f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -410,6 +410,10 @@ config PARAVIRT over full virtualization. However, when run without a hypervisor the kernel is theoretically slower and slightly larger. +config PARAVIRT_CLOCK + bool + default n + endif config MEMTEST_BOOTPARAM diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 5e618c3b4720..77807d4769c9 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -82,6 +82,7 @@ obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o obj-$(CONFIG_KVM_GUEST) += kvm.o obj-$(CONFIG_KVM_CLOCK) += kvmclock.o obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o +obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c new file mode 100644 index 000000000000..05fbe9a0325a --- /dev/null +++ b/arch/x86/kernel/pvclock.c @@ -0,0 +1,141 @@ +/* paravirtual clock -- common code used by kvm/xen + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +*/ + +#include +#include +#include + +/* + * These are perodically updated + * xen: magic shared_info page + * kvm: gpa registered via msr + * and then copied here. + */ +struct pvclock_shadow_time { + u64 tsc_timestamp; /* TSC at last update of time vals. */ + u64 system_timestamp; /* Time, in nanosecs, since boot. */ + u32 tsc_to_nsec_mul; + int tsc_shift; + u32 version; +}; + +/* + * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, + * yielding a 64-bit result. + */ +static inline u64 scale_delta(u64 delta, u32 mul_frac, int shift) +{ + u64 product; +#ifdef __i386__ + u32 tmp1, tmp2; +#endif + + if (shift < 0) + delta >>= -shift; + else + delta <<= shift; + +#ifdef __i386__ + __asm__ ( + "mul %5 ; " + "mov %4,%%eax ; " + "mov %%edx,%4 ; " + "mul %5 ; " + "xor %5,%5 ; " + "add %4,%%eax ; " + "adc %5,%%edx ; " + : "=A" (product), "=r" (tmp1), "=r" (tmp2) + : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); +#elif __x86_64__ + __asm__ ( + "mul %%rdx ; shrd $32,%%rdx,%%rax" + : "=a" (product) : "0" (delta), "d" ((u64)mul_frac) ); +#else +#error implement me! +#endif + + return product; +} + +static u64 pvclock_get_nsec_offset(struct pvclock_shadow_time *shadow) +{ + u64 delta = native_read_tsc() - shadow->tsc_timestamp; + return scale_delta(delta, shadow->tsc_to_nsec_mul, shadow->tsc_shift); +} + +/* + * Reads a consistent set of time-base values from hypervisor, + * into a shadow data area. + */ +static unsigned pvclock_get_time_values(struct pvclock_shadow_time *dst, + struct pvclock_vcpu_time_info *src) +{ + do { + dst->version = src->version; + rmb(); /* fetch version before data */ + dst->tsc_timestamp = src->tsc_timestamp; + dst->system_timestamp = src->system_time; + dst->tsc_to_nsec_mul = src->tsc_to_system_mul; + dst->tsc_shift = src->tsc_shift; + rmb(); /* test version after fetching data */ + } while ((src->version & 1) || (dst->version != src->version)); + + return dst->version; +} + +cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) +{ + struct pvclock_shadow_time shadow; + unsigned version; + cycle_t ret, offset; + + do { + version = pvclock_get_time_values(&shadow, src); + barrier(); + offset = pvclock_get_nsec_offset(&shadow); + ret = shadow.system_timestamp + offset; + barrier(); + } while (version != src->version); + + return ret; +} + +void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, + struct pvclock_vcpu_time_info *vcpu_time, + struct timespec *ts) +{ + u32 version; + u64 delta; + struct timespec now; + + /* get wallclock at system boot */ + do { + version = wall_clock->version; + rmb(); /* fetch version before time */ + now.tv_sec = wall_clock->sec; + now.tv_nsec = wall_clock->nsec; + rmb(); /* fetch time before checking version */ + } while ((wall_clock->version & 1) || (version != wall_clock->version)); + + delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */ + delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; + + now.tv_nsec = do_div(delta, NSEC_PER_SEC); + now.tv_sec = delta; + + set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); +} diff --git a/include/asm-x86/pvclock-abi.h b/include/asm-x86/pvclock-abi.h new file mode 100644 index 000000000000..6857f840b243 --- /dev/null +++ b/include/asm-x86/pvclock-abi.h @@ -0,0 +1,42 @@ +#ifndef _ASM_X86_PVCLOCK_ABI_H_ +#define _ASM_X86_PVCLOCK_ABI_H_ +#ifndef __ASSEMBLY__ + +/* + * These structs MUST NOT be changed. + * They are the ABI between hypervisor and guest OS. + * Both Xen and KVM are using this. + * + * pvclock_vcpu_time_info holds the system time and the tsc timestamp + * of the last update. So the guest can use the tsc delta to get a + * more precise system time. There is one per virtual cpu. + * + * pvclock_wall_clock references the point in time when the system + * time was zero (usually boot time), thus the guest calculates the + * current wall clock by adding the system time. + * + * Protocol for the "version" fields is: hypervisor raises it (making + * it uneven) before it starts updating the fields and raises it again + * (making it even) when it is done. Thus the guest can make sure the + * time values it got are consistent by checking the version before + * and after reading them. + */ + +struct pvclock_vcpu_time_info { + u32 version; + u32 pad0; + u64 tsc_timestamp; + u64 system_time; + u32 tsc_to_system_mul; + s8 tsc_shift; + u8 pad[3]; +} __attribute__((__packed__)); /* 32 bytes */ + +struct pvclock_wall_clock { + u32 version; + u32 sec; + u32 nsec; +} __attribute__((__packed__)); + +#endif /* __ASSEMBLY__ */ +#endif /* _ASM_X86_PVCLOCK_ABI_H_ */ diff --git a/include/asm-x86/pvclock.h b/include/asm-x86/pvclock.h new file mode 100644 index 000000000000..85b1bba8e0a3 --- /dev/null +++ b/include/asm-x86/pvclock.h @@ -0,0 +1,13 @@ +#ifndef _ASM_X86_PVCLOCK_H_ +#define _ASM_X86_PVCLOCK_H_ + +#include +#include + +/* some helper functions for xen and kvm pv clock sources */ +cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); +void pvclock_read_wallclock(struct pvclock_wall_clock *wall, + struct pvclock_vcpu_time_info *vcpu, + struct timespec *ts); + +#endif /* _ASM_X86_PVCLOCK_H_ */ -- cgit v1.2.3 From 1c7b67f7576c4ca2a344379a4a29eec8fe8e7935 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 3 Jun 2008 16:17:30 +0200 Subject: x86: Make xen use the paravirt clocksource structs and functions This patch updates the xen guest to use the pvclock structs and helper functions. Signed-off-by: Gerd Hoffmann Acked-by: Jeremy Fitzhardinge Signed-off-by: Avi Kivity --- arch/x86/xen/Kconfig | 1 + arch/x86/xen/time.c | 132 ++++---------------------------------------- include/xen/interface/xen.h | 7 +-- 3 files changed, 16 insertions(+), 124 deletions(-) (limited to 'include') diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index 2e641be2737e..3a4f16aea4bf 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -5,6 +5,7 @@ config XEN bool "Xen guest support" select PARAVIRT + select PARAVIRT_CLOCK depends on X86_32 depends on X86_CMPXCHG && X86_TSC && !(X86_VISWS || X86_VOYAGER) help diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 52b2e3856980..41e217503c96 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -14,6 +14,7 @@ #include #include +#include #include #include @@ -31,17 +32,6 @@ static cycle_t xen_clocksource_read(void); -/* These are perodically updated in shared_info, and then copied here. */ -struct shadow_time_info { - u64 tsc_timestamp; /* TSC at last update of time vals. */ - u64 system_timestamp; /* Time, in nanosecs, since boot. */ - u32 tsc_to_nsec_mul; - int tsc_shift; - u32 version; -}; - -static DEFINE_PER_CPU(struct shadow_time_info, shadow_time); - /* runstate info updated by Xen */ static DEFINE_PER_CPU(struct vcpu_runstate_info, runstate); @@ -211,7 +201,7 @@ unsigned long long xen_sched_clock(void) unsigned long xen_cpu_khz(void) { u64 xen_khz = 1000000ULL << 32; - const struct vcpu_time_info *info = + const struct pvclock_vcpu_time_info *info = &HYPERVISOR_shared_info->vcpu_info[0].time; do_div(xen_khz, info->tsc_to_system_mul); @@ -223,121 +213,26 @@ unsigned long xen_cpu_khz(void) return xen_khz; } -/* - * Reads a consistent set of time-base values from Xen, into a shadow data - * area. - */ -static unsigned get_time_values_from_xen(void) -{ - struct vcpu_time_info *src; - struct shadow_time_info *dst; - - /* src is shared memory with the hypervisor, so we need to - make sure we get a consistent snapshot, even in the face of - being preempted. */ - src = &__get_cpu_var(xen_vcpu)->time; - dst = &__get_cpu_var(shadow_time); - - do { - dst->version = src->version; - rmb(); /* fetch version before data */ - dst->tsc_timestamp = src->tsc_timestamp; - dst->system_timestamp = src->system_time; - dst->tsc_to_nsec_mul = src->tsc_to_system_mul; - dst->tsc_shift = src->tsc_shift; - rmb(); /* test version after fetching data */ - } while ((src->version & 1) | (dst->version ^ src->version)); - - return dst->version; -} - -/* - * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, - * yielding a 64-bit result. - */ -static inline u64 scale_delta(u64 delta, u32 mul_frac, int shift) -{ - u64 product; -#ifdef __i386__ - u32 tmp1, tmp2; -#endif - - if (shift < 0) - delta >>= -shift; - else - delta <<= shift; - -#ifdef __i386__ - __asm__ ( - "mul %5 ; " - "mov %4,%%eax ; " - "mov %%edx,%4 ; " - "mul %5 ; " - "xor %5,%5 ; " - "add %4,%%eax ; " - "adc %5,%%edx ; " - : "=A" (product), "=r" (tmp1), "=r" (tmp2) - : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); -#elif __x86_64__ - __asm__ ( - "mul %%rdx ; shrd $32,%%rdx,%%rax" - : "=a" (product) : "0" (delta), "d" ((u64)mul_frac) ); -#else -#error implement me! -#endif - - return product; -} - -static u64 get_nsec_offset(struct shadow_time_info *shadow) -{ - u64 now, delta; - now = native_read_tsc(); - delta = now - shadow->tsc_timestamp; - return scale_delta(delta, shadow->tsc_to_nsec_mul, shadow->tsc_shift); -} - static cycle_t xen_clocksource_read(void) { - struct shadow_time_info *shadow = &get_cpu_var(shadow_time); + struct pvclock_vcpu_time_info *src; cycle_t ret; - unsigned version; - - do { - version = get_time_values_from_xen(); - barrier(); - ret = shadow->system_timestamp + get_nsec_offset(shadow); - barrier(); - } while (version != __get_cpu_var(xen_vcpu)->time.version); - - put_cpu_var(shadow_time); + src = &get_cpu_var(xen_vcpu)->time; + ret = pvclock_clocksource_read(src); + put_cpu_var(xen_vcpu); return ret; } static void xen_read_wallclock(struct timespec *ts) { - const struct shared_info *s = HYPERVISOR_shared_info; - u32 version; - u64 delta; - struct timespec now; - - /* get wallclock at system boot */ - do { - version = s->wc_version; - rmb(); /* fetch version before time */ - now.tv_sec = s->wc_sec; - now.tv_nsec = s->wc_nsec; - rmb(); /* fetch time before checking version */ - } while ((s->wc_version & 1) | (version ^ s->wc_version)); + struct shared_info *s = HYPERVISOR_shared_info; + struct pvclock_wall_clock *wall_clock = &(s->wc); + struct pvclock_vcpu_time_info *vcpu_time; - delta = xen_clocksource_read(); /* time since system boot */ - delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; - - now.tv_nsec = do_div(delta, NSEC_PER_SEC); - now.tv_sec = delta; - - set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); + vcpu_time = &get_cpu_var(xen_vcpu)->time; + pvclock_read_wallclock(wall_clock, vcpu_time, ts); + put_cpu_var(xen_vcpu); } unsigned long xen_get_wallclock(void) @@ -345,7 +240,6 @@ unsigned long xen_get_wallclock(void) struct timespec ts; xen_read_wallclock(&ts); - return ts.tv_sec; } @@ -569,8 +463,6 @@ __init void xen_time_init(void) { int cpu = smp_processor_id(); - get_time_values_from_xen(); - clocksource_register(&xen_clocksource); if (HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL) == 0) { diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 9b018da48cf3..819a0331cda9 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -10,6 +10,7 @@ #define __XEN_PUBLIC_XEN_H__ #include +#include /* * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS). @@ -336,7 +337,7 @@ struct vcpu_info { uint8_t evtchn_upcall_mask; unsigned long evtchn_pending_sel; struct arch_vcpu_info arch; - struct vcpu_time_info time; + struct pvclock_vcpu_time_info time; }; /* 64 bytes (x86) */ /* @@ -384,9 +385,7 @@ struct shared_info { * Wallclock time: updated only by control software. Guests should base * their gettimeofday() syscall on this wallclock-base value. */ - uint32_t wc_version; /* Version counter: see vcpu_time_info_t. */ - uint32_t wc_sec; /* Secs 00:00:00 UTC, Jan 1, 1970. */ - uint32_t wc_nsec; /* Nsecs 00:00:00 UTC, Jan 1, 1970. */ + struct pvclock_wall_clock wc; struct arch_shared_info arch; -- cgit v1.2.3 From 50d0a0f987b83a8dadb1134d834e35ec410392b5 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 3 Jun 2008 16:17:31 +0200 Subject: KVM: Make kvm host use the paravirt clocksource structs This patch updates the kvm host code to use the pvclock structs. It also makes the paravirt clock compatible with Xen. Signed-off-by: Gerd Hoffmann Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 75 ++++++++++++++++++++++++++++++++++++++-------- include/asm-x86/kvm_host.h | 4 ++- 2 files changed, 65 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b08812d6b34c..63a77caa59f1 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -492,8 +492,8 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data) static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) { static int version; - struct kvm_wall_clock wc; - struct timespec wc_ts; + struct pvclock_wall_clock wc; + struct timespec now, sys, boot; if (!wall_clock) return; @@ -502,10 +502,19 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) kvm_write_guest(kvm, wall_clock, &version, sizeof(version)); - wc_ts = current_kernel_time(); - wc.wc_sec = wc_ts.tv_sec; - wc.wc_nsec = wc_ts.tv_nsec; - wc.wc_version = version; + /* + * The guest calculates current wall clock time by adding + * system time (updated by kvm_write_guest_time below) to the + * wall clock specified here. guest system time equals host + * system time for us, thus we must fill in host boot time here. + */ + now = current_kernel_time(); + ktime_get_ts(&sys); + boot = ns_to_timespec(timespec_to_ns(&now) - timespec_to_ns(&sys)); + + wc.sec = boot.tv_sec; + wc.nsec = boot.tv_nsec; + wc.version = version; kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc)); @@ -513,6 +522,45 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) kvm_write_guest(kvm, wall_clock, &version, sizeof(version)); } +static uint32_t div_frac(uint32_t dividend, uint32_t divisor) +{ + uint32_t quotient, remainder; + + /* Don't try to replace with do_div(), this one calculates + * "(dividend << 32) / divisor" */ + __asm__ ( "divl %4" + : "=a" (quotient), "=d" (remainder) + : "0" (0), "1" (dividend), "r" (divisor) ); + return quotient; +} + +static void kvm_set_time_scale(uint32_t tsc_khz, struct pvclock_vcpu_time_info *hv_clock) +{ + uint64_t nsecs = 1000000000LL; + int32_t shift = 0; + uint64_t tps64; + uint32_t tps32; + + tps64 = tsc_khz * 1000LL; + while (tps64 > nsecs*2) { + tps64 >>= 1; + shift--; + } + + tps32 = (uint32_t)tps64; + while (tps32 <= (uint32_t)nsecs) { + tps32 <<= 1; + shift++; + } + + hv_clock->tsc_shift = shift; + hv_clock->tsc_to_system_mul = div_frac(nsecs, tps32); + + pr_debug("%s: tsc_khz %u, tsc_shift %d, tsc_mul %u\n", + __FUNCTION__, tsc_khz, hv_clock->tsc_shift, + hv_clock->tsc_to_system_mul); +} + static void kvm_write_guest_time(struct kvm_vcpu *v) { struct timespec ts; @@ -523,6 +571,11 @@ static void kvm_write_guest_time(struct kvm_vcpu *v) if ((!vcpu->time_page)) return; + if (unlikely(vcpu->hv_clock_tsc_khz != tsc_khz)) { + kvm_set_time_scale(tsc_khz, &vcpu->hv_clock); + vcpu->hv_clock_tsc_khz = tsc_khz; + } + /* Keep irq disabled to prevent changes to the clock */ local_irq_save(flags); kvm_get_msr(v, MSR_IA32_TIME_STAMP_COUNTER, @@ -537,14 +590,14 @@ static void kvm_write_guest_time(struct kvm_vcpu *v) /* * The interface expects us to write an even number signaling that the * update is finished. Since the guest won't see the intermediate - * state, we just write "2" at the end + * state, we just increase by 2 at the end. */ - vcpu->hv_clock.version = 2; + vcpu->hv_clock.version += 2; shared_kaddr = kmap_atomic(vcpu->time_page, KM_USER0); memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock, - sizeof(vcpu->hv_clock)); + sizeof(vcpu->hv_clock)); kunmap_atomic(shared_kaddr, KM_USER0); @@ -599,10 +652,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) /* ...but clean it before doing the actual write */ vcpu->arch.time_offset = data & ~(PAGE_MASK | 1); - vcpu->arch.hv_clock.tsc_to_system_mul = - clocksource_khz2mult(tsc_khz, 22); - vcpu->arch.hv_clock.tsc_shift = 22; - down_read(¤t->mm->mmap_sem); vcpu->arch.time_page = gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT); diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index 1d8cd01fa514..844f2a89afbc 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -18,6 +18,7 @@ #include #include +#include #include #define KVM_MAX_VCPUS 16 @@ -282,7 +283,8 @@ struct kvm_vcpu_arch { struct x86_emulate_ctxt emulate_ctxt; gpa_t time; - struct kvm_vcpu_time_info hv_clock; + struct pvclock_vcpu_time_info hv_clock; + unsigned int hv_clock_tsc_khz; unsigned int time_offset; struct page *time_page; }; -- cgit v1.2.3 From 6b1ed9086592fd4b066daae222751bb6757ca5eb Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 3 Jun 2008 16:17:33 +0200 Subject: KVM: Remove now unused structs from kvm_para.h The kvm_* structs are obsoleted by the pvclock_* ones. Now all users have been switched over and the old structs can be dropped. Signed-off-by: Gerd Hoffmann Signed-off-by: Avi Kivity --- include/asm-x86/kvm_para.h | 18 ------------------ 1 file changed, 18 deletions(-) (limited to 'include') diff --git a/include/asm-x86/kvm_para.h b/include/asm-x86/kvm_para.h index 509845942070..bfd9900742bf 100644 --- a/include/asm-x86/kvm_para.h +++ b/include/asm-x86/kvm_para.h @@ -48,24 +48,6 @@ struct kvm_mmu_op_release_pt { #ifdef __KERNEL__ #include -/* xen binary-compatible interface. See xen headers for details */ -struct kvm_vcpu_time_info { - uint32_t version; - uint32_t pad0; - uint64_t tsc_timestamp; - uint64_t system_time; - uint32_t tsc_to_system_mul; - int8_t tsc_shift; - int8_t pad[3]; -} __attribute__((__packed__)); /* 32 bytes */ - -struct kvm_wall_clock { - uint32_t wc_version; - uint32_t wc_sec; - uint32_t wc_nsec; -} __attribute__((__packed__)); - - extern void kvmclock_init(void); -- cgit v1.2.3