From: "Radim Krčmář" <rkrcmar@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Gleb Natapov <gleb@kernel.org>,
Raghavendra KT <raghavendra.kt@linux.vnet.ibm.com>,
Vinod Chegu <chegu_vinod@hp.com>, Hui-Zhi <hui-zhi.zhao@hp.com>
Subject: [PATCH 8/9] KVM: VMX: runtime knobs for dynamic PLE window
Date: Tue, 19 Aug 2014 22:35:35 +0200 [thread overview]
Message-ID: <1408480536-8240-9-git-send-email-rkrcmar@redhat.com> (raw)
In-Reply-To: <1408480536-8240-1-git-send-email-rkrcmar@redhat.com>
ple_window is updated on every vmentry, so there is no reason to have it
read-only anymore.
ple_window_* weren't writable to prevent runtime overflow races;
they are mitigated by clamping the value of ple_window.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
If we decide to ignore insane overflows, last two hunks can be dropped.
arch/x86/kvm/vmx.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c6cfb71..d7f58e8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -134,19 +134,19 @@ static int ple_gap = KVM_VMX_DEFAULT_PLE_GAP;
module_param(ple_gap, int, S_IRUGO);
static int ple_window = KVM_VMX_DEFAULT_PLE_WINDOW;
-module_param(ple_window, int, S_IRUGO);
+module_param(ple_window, int, S_IRUGO | S_IWUSR);
/* Default doubles per-vcpu window every exit. */
static int ple_window_grow = KVM_VMX_DEFAULT_PLE_WINDOW_GROW;
-module_param(ple_window_grow, int, S_IRUGO);
+module_param(ple_window_grow, int, S_IRUGO | S_IWUSR);
/* Default resets per-vcpu window every exit to ple_window. */
static int ple_window_shrink = KVM_VMX_DEFAULT_PLE_WINDOW_SHRINK;
-module_param(ple_window_shrink, int, S_IRUGO);
+module_param(ple_window_shrink, int, S_IRUGO | S_IWUSR);
/* Default is to compute the maximum so we can never overflow. */
static int ple_window_max = INT_MAX / KVM_VMX_DEFAULT_PLE_WINDOW_GROW;
-module_param(ple_window_max, int, S_IRUGO);
+module_param(ple_window_max, int, S_IRUGO | S_IWUSR);
extern const ulong vmx_return;
@@ -5694,7 +5694,8 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
out:
return ret;
}
-#define make_ple_window_modifier(type, oplt, opge, cmp, bound) \
+
+#define make_ple_window_modifier(type, oplt, opge) \
static void type##_ple_window(struct kvm_vcpu *vcpu) \
{ \
struct vcpu_vmx *vmx = to_vmx(vcpu); \
@@ -5708,13 +5709,13 @@ static void type##_ple_window(struct kvm_vcpu *vcpu) \
else \
new = old opge ple_window_##type; \
\
- vmx->ple_window = cmp(new, bound); \
+ vmx->ple_window = clamp(new, ple_window, ple_window_max); \
\
trace_kvm_ple_window_##type(vcpu->vcpu_id, vmx->ple_window, old); \
}
-make_ple_window_modifier(grow, *, +, min, ple_window_max)
-make_ple_window_modifier(shrink, /, -, max, ple_window)
+make_ple_window_modifier(grow, *, +) /* grow_ple_window */
+make_ple_window_modifier(shrink, /, -) /* shrink_ple_window */
/*
* Indicate a busy-waiting vcpu in spinlock. We do not enable the PAUSE
--
2.0.4
next prev parent reply other threads:[~2014-08-19 20:38 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-19 20:35 [PATCH 0/9] Dynamic Pause Loop Exiting window Radim Krčmář
2014-08-19 20:35 ` [PATCH 1/9] KVM: add kvm_arch_sched_in Radim Krčmář
2014-08-20 7:47 ` Christian Borntraeger
2014-08-20 12:56 ` Radim Krčmář
2014-08-19 20:35 ` [PATCH 2/9] KVM: x86: introduce sched_in to kvm_x86_ops Radim Krčmář
2014-08-19 20:35 ` [PATCH 3/9] KVM: VMX: make PLE window per-vcpu Radim Krčmář
2014-08-20 7:13 ` Paolo Bonzini
2014-08-20 12:26 ` Radim Krčmář
2014-08-19 20:35 ` [PATCH 4/9] KVM: VMX: dynamise PLE window Radim Krčmář
2014-08-19 20:35 ` [PATCH 5/9] KVM: VMX: clamp " Radim Krčmář
2014-08-20 7:18 ` Paolo Bonzini
2014-08-20 12:46 ` Radim Krčmář
2014-08-19 20:35 ` [PATCH 6/9] KVM: trace kvm_ple_window grow/shrink Radim Krčmář
2014-08-19 20:35 ` [PATCH 7/9] KVM: VMX: abstract ple_window modifiers Radim Krčmář
2014-08-20 7:02 ` Paolo Bonzini
2014-08-20 12:25 ` Radim Krčmář
2014-08-19 20:35 ` Radim Krčmář [this message]
2014-08-19 20:35 ` [PATCH 9/9] KVM: VMX: automatic PLE window maximum Radim Krčmář
2014-08-20 7:16 ` Paolo Bonzini
2014-08-20 7:18 ` Paolo Bonzini
2014-08-20 12:41 ` Radim Krčmář
2014-08-20 13:15 ` Paolo Bonzini
2014-08-20 15:31 ` Radim Krčmář
2014-08-20 15:34 ` Paolo Bonzini
2014-08-20 16:01 ` Radim Krčmář
2014-08-20 16:03 ` Paolo Bonzini
2014-08-20 16:26 ` Radim Krčmář
2014-08-21 6:48 ` [PATCH 0/9] Dynamic Pause Loop Exiting window Zhao, Hui-Zhi (Steven, HPservers-Core-OE-PSC)
2014-08-21 6:48 ` Zhao, Hui-Zhi (Steven, HPservers-Core-OE-PSC)
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