x86/hvm: Constify the read side of vlapic handling

This is in preparation to make hvm_x2apic_msr_read() take a const vcpu
pointer.  One modification is to alter vlapic_get_tmcct() to not use current.

This in turn needs an alteration to hvm_get_guest_time_fixed(), which is safe
because the only mutable action it makes is to take the domain plt lock.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 7387f91fe04e4f73d9f7b81ccd0fca6c1e2096ca..e715729f77d20575ebb05665df45cdaa686b70d1 100644 (file)
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -171,12 +171,12 @@ void vlapic_set_irq(struct vlapic *vlapic, uint8_t vec, uint8_t trig)
         vcpu_kick(target);
 }
 
-static int vlapic_find_highest_isr(struct vlapic *vlapic)
+static int vlapic_find_highest_isr(const struct vlapic *vlapic)
 {
     return vlapic_find_highest_vector(&vlapic->regs->data[APIC_ISR]);
 }
 
-static uint32_t vlapic_get_ppr(struct vlapic *vlapic)
+static uint32_t vlapic_get_ppr(const struct vlapic *vlapic)
 {
     uint32_t tpr, isrv, ppr;
     int isr;
@@ -550,9 +550,9 @@ void vlapic_ipi(
     }
 }
 
-static uint32_t vlapic_get_tmcct(struct vlapic *vlapic)
+static uint32_t vlapic_get_tmcct(const struct vlapic *vlapic)
 {
-    struct vcpu *v = current;
+    const struct vcpu *v = const_vlapic_vcpu(vlapic);
     uint32_t tmcct = 0, tmict = vlapic_get_reg(vlapic, APIC_TMICT);
     uint64_t counter_passed;
 
@@ -590,7 +590,8 @@ static void vlapic_set_tdcr(struct vlapic *vlapic, unsigned int val)
                 "timer_divisor: %d", vlapic->hw.timer_divisor);
 }
 
-static uint32_t vlapic_read_aligned(struct vlapic *vlapic, unsigned int offset)
+static uint32_t vlapic_read_aligned(const struct vlapic *vlapic,
+                                    unsigned int offset)
 {
     switch ( offset )
     {
@@ -680,7 +681,7 @@ int hvm_x2apic_msr_read(struct vcpu *v, unsigned int msr, uint64_t *msr_content)
             REGBLOCK(ISR) | REGBLOCK(TMR) | REGBLOCK(IRR)
 #undef REGBLOCK
         };
-    struct vlapic *vlapic = vcpu_vlapic(v);
+    const struct vlapic *vlapic = vcpu_vlapic(v);
     uint32_t high = 0, reg = msr - MSR_IA32_APICBASE_MSR, offset = reg << 4;
 
     if ( !vlapic_x2apic_mode(vlapic) ||

diff --git a/xen/arch/x86/hvm/vpt.c b/xen/arch/x86/hvm/vpt.c
index 181f4cb6317c524767d1ed9dd47190122abb405d..9d27b483b28ce13f8f055e0ee34b9660a98b6022 100644 (file)
--- a/xen/arch/x86/hvm/vpt.c
+++ b/xen/arch/x86/hvm/vpt.c
@@ -35,7 +35,7 @@ void hvm_init_guest_time(struct domain *d)
     pl->last_guest_time = 0;
 }
 
-u64 hvm_get_guest_time_fixed(struct vcpu *v, u64 at_tsc)
+uint64_t hvm_get_guest_time_fixed(const struct vcpu *v, uint64_t at_tsc)
 {
     struct pl_time *pl = v->domain->arch.hvm_domain.pl_time;
     u64 now;

diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index ca3a3343fdaf5434e8a87f609ac1f019a275a429..9aa6c72d9d00db2617aac29f2ff0c19efaf5f010 100644 (file)
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -273,7 +273,7 @@ u64 hvm_get_tsc_scaling_ratio(u32 gtsc_khz);
 
 void hvm_init_guest_time(struct domain *d);
 void hvm_set_guest_time(struct vcpu *v, u64 guest_time);
-u64 hvm_get_guest_time_fixed(struct vcpu *v, u64 at_tsc);
+uint64_t hvm_get_guest_time_fixed(const struct vcpu *v, uint64_t at_tsc);
 #define hvm_get_guest_time(v) hvm_get_guest_time_fixed(v, 0)
 
 int vmsi_deliver(