[PATCH 2/7] KVM: x86: change vcpu->arch.switch_db_regs to a bit mask

Paolo Bonzini
2014-03-07T11:42:46Z

The next patch will add another bit that we can test with the
same "if".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 6 +++++-
arch/x86/kvm/x86.c | 4 +++-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 85be627ef5de..5ef59d3b6c63 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -337,6 +337,10 @@ struct kvm_pmu {
u64 reprogram_pmi;
};

+enum {
+ KVM_DEBUGREG_BP_ENABLED = 1,
+};
+
struct kvm_vcpu_arch {
/*
* rip and regs accesses must go through
@@ -463,7 +467,7 @@ struct kvm_vcpu_arch {
struct mtrr_state_type mtrr_state;
u32 pat;

- int switch_db_regs;
+ unsigned switch_db_regs;
unsigned long db[KVM_NR_DB_REGS];
unsigned long dr6;
unsigned long dr7;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a45bcac45645..252b47e85c69 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -759,7 +759,9 @@ static void kvm_update_dr7(struct kvm_vcpu *vcpu)
else
dr7 = vcpu->arch.dr7;
kvm_x86_ops->set_dr7(vcpu, dr7);
- vcpu->arch.switch_db_regs = (dr7 & DR7_BP_EN_MASK);
+ vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
+ if (dr7 & DR7_BP_EN_MASK)
+ vcpu->arch.switch_db_regs |= KVM_DEBUGREG_BP_ENABLED;
}

static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
--
1.8.3.1