On 12/10/2009 08:38 PM, oritw@xxxxxxxxxx wrote:
From: Orit Wasserman<oritw@xxxxxxxxxx>
What exactly is the simplification? Is it intended to have a functional
change?
---
arch/x86/kvm/vmx.c | 27 +++++++++++++++++----------
1 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8745d44..de1f596 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1244,8 +1244,6 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
u32 eb;
eb = (1u<< PF_VECTOR) | (1u<< UD_VECTOR) | (1u<< MC_VECTOR);
- if (!vcpu->fpu_active)
- eb |= 1u<< NM_VECTOR;
/*
* Unconditionally intercept #DB so we can maintain dr6 without
* reading it every exit.
@@ -1463,10 +1461,6 @@ static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
if (vcpu->fpu_active)
return;
vcpu->fpu_active = 1;
- vmcs_clear_bits(GUEST_CR0, X86_CR0_TS);
- if (vcpu->arch.cr0& X86_CR0_TS)
- vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
- update_exception_bitmap(vcpu);
}
static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
@@ -1474,8 +1468,6 @@ static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
if (!vcpu->fpu_active)
return;
vcpu->fpu_active = 0;
- vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
- update_exception_bitmap(vcpu);
}
static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
@@ -2715,8 +2707,10 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
vmx_flush_tlb(vcpu);
vmcs_writel(GUEST_CR3, guest_cr3);
- if (vcpu->arch.cr0& X86_CR0_PE)
- vmx_fpu_deactivate(vcpu);
+ if (vcpu->arch.cr0& X86_CR0_PE) {
+ if (guest_cr3 != vmcs_readl(GUEST_CR3))
+ vmx_fpu_deactivate(vcpu);
+ }
Why the added cr3 check? It may make sense, but it isn't a simplification.
static void vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
@@ -5208,6 +5202,19 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (vcpu->arch.switch_db_regs)
get_debugreg(vcpu->arch.dr6, 6);
+ if (vcpu->fpu_active) {
+ if (vmcs_readl(CR0_READ_SHADOW)& X86_CR0_TS)
+ vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
+ else
+ vmcs_clear_bits(GUEST_CR0, X86_CR0_TS);
+ vmcs_write32(EXCEPTION_BITMAP,
+ vmcs_read32(EXCEPTION_BITMAP)& ~(1u<< NM_VECTOR));
+ } else {
+ vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
+ vmcs_write32(EXCEPTION_BITMAP,
+ vmcs_read32(EXCEPTION_BITMAP) | (1u<< NM_VECTOR));
+ }
This is executed unconditionally, so the vmreads/vmwrites take place
every time. Need to cache the previous fpu_active state and only take
action if it changed.
Since this is a large piece of code, move it to a function.
Please post this as the first patch (or better, separately), so I can
apply it independently of the rest.
--
error compiling committee.c: too many arguments to function
--
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