From f3ac1a4b667eeffcedf779f45529c95d66ddc71a Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Date: Tue, 16 Oct 2012 20:07:03 +0800
Subject: [PATCH 1/3] KVM: MMU: fix release noslot pfn
We can not directly call kvm_release_pfn_clean to release the pfn
since we can meet noslot pfn which is used to cache mmio info into
spte
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/mmu.c | 3 +--
virt/kvm/kvm_main.c | 4 +---
2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d289fee1ffb8..6f85fe0bf958 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2497,8 +2497,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
}
}
- if (!is_error_pfn(pfn))
- kvm_release_pfn_clean(pfn);
+ kvm_release_pfn_clean(pfn);
}
static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c353b4599cec..a65bc02a3755 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1322,9 +1322,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean);
void kvm_release_pfn_clean(pfn_t pfn)
{
- WARN_ON(is_error_pfn(pfn));
-
- if (!kvm_is_mmio_pfn(pfn))
+ if (!is_error_pfn(pfn) && !kvm_is_mmio_pfn(pfn))
put_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
From 7f46ddbd487e0d0528d89534fdfb31d885977804 Mon Sep 17 00:00:00 2001
From: Gleb Natapov <gleb@redhat.com>
Date: Sun, 14 Oct 2012 13:08:58 +0200
Subject: [PATCH 2/3] KVM: apic: fix LDR calculation in x2apic mode
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/lapic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index c6e6b721b6ee..43e9fadca5d0 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1311,7 +1311,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
vcpu->arch.apic_base = value;
if (apic_x2apic_mode(apic)) {
u32 id = kvm_apic_id(apic);
- u32 ldr = ((id & ~0xf) << 16) | (1 << (id & 0xf));
+ u32 ldr = ((id >> 4) << 16) | (1 << (id & 0xf));
kvm_apic_set_ldr(apic, ldr);
}
apic->base_address = apic->vcpu->arch.apic_base &
From c5e015d4949aa665c486cae6884beb00b97e3dea Mon Sep 17 00:00:00 2001
From: Sasha Levin <sasha.levin@oracle.com>
Date: Fri, 19 Oct 2012 12:11:55 -0400
Subject: [PATCH 3/3] KVM guest: exit idleness when handling
KVM_PV_REASON_PAGE_NOT_PRESENT
KVM_PV_REASON_PAGE_NOT_PRESENT kicks cpu out of idleness, but we haven't
marked that spot as an exit from idleness.
Not doing so can cause RCU warnings such as:
[ 732.788386] ===============================
[ 732.789803] [ INFO: suspicious RCU usage. ]
[ 732.790032] 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63 Tainted: G W
[ 732.790032] -------------------------------
[ 732.790032] include/linux/rcupdate.h:738 rcu_read_lock() used illegally while idle!
[ 732.790032]
[ 732.790032] other info that might help us debug this:
[ 732.790032]
[ 732.790032]
[ 732.790032] RCU used illegally from idle CPU!
[ 732.790032] rcu_scheduler_active = 1, debug_locks = 1
[ 732.790032] RCU used illegally from extended quiescent state!
[ 732.790032] 2 locks held by trinity-child31/8252:
[ 732.790032] #0: (&rq->lock){-.-.-.}, at: [<ffffffff83a67528>] __schedule+0x178/0x8f0
[ 732.790032] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff81152bde>] cpuacct_charge+0xe/0x200
[ 732.790032]
[ 732.790032] stack backtrace:
[ 732.790032] Pid: 8252, comm: trinity-child31 Tainted: G W 3.7.0-rc1-next-20121019-sasha-00002-g6d8d02d-dirty #63
[ 732.790032] Call Trace:
[ 732.790032] [<ffffffff8118266b>] lockdep_rcu_suspicious+0x10b/0x120
[ 732.790032] [<ffffffff81152c60>] cpuacct_charge+0x90/0x200
[ 732.790032] [<ffffffff81152bde>] ? cpuacct_charge+0xe/0x200
[ 732.790032] [<ffffffff81158093>] update_curr+0x1a3/0x270
[ 732.790032] [<ffffffff81158a6a>] dequeue_entity+0x2a/0x210
[ 732.790032] [<ffffffff81158ea5>] dequeue_task_fair+0x45/0x130
[ 732.790032] [<ffffffff8114ae29>] dequeue_task+0x89/0xa0
[ 732.790032] [<ffffffff8114bb9e>] deactivate_task+0x1e/0x20
[ 732.790032] [<ffffffff83a67c29>] __schedule+0x879/0x8f0
[ 732.790032] [<ffffffff8117e20d>] ? trace_hardirqs_off+0xd/0x10
[ 732.790032] [<ffffffff810a37a5>] ? kvm_async_pf_task_wait+0x1d5/0x2b0
[ 732.790032] [<ffffffff83a67cf5>] schedule+0x55/0x60
[ 732.790032] [<ffffffff810a37c4>] kvm_async_pf_task_wait+0x1f4/0x2b0
[ 732.790032] [<ffffffff81139e50>] ? abort_exclusive_wait+0xb0/0xb0
[ 732.790032] [<ffffffff81139c25>] ? prepare_to_wait+0x25/0x90
[ 732.790032] [<ffffffff810a3a66>] do_async_page_fault+0x56/0xa0
[ 732.790032] [<ffffffff83a6a6e8>] async_page_fault+0x28/0x30
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kernel/kvm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b3e5e51bc907..4180a874c764 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -247,7 +247,10 @@ do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
break;
case KVM_PV_REASON_PAGE_NOT_PRESENT:
/* page is swapped out by the host. */
+ rcu_irq_enter();
+ exit_idle();
kvm_async_pf_task_wait((u32)read_cr2());
+ rcu_irq_exit();
break;
case KVM_PV_REASON_PAGE_READY:
rcu_irq_enter();