KVM: x86: accessors for guest registers
As suggested by Avi, introduce accessors to read/write guest registers.
This simplifies the ->cache_regs/->decache_regs interface, and improves
register caching which is important for VMX, where the cost of
vmcs_read/vmcs_write is significant.
[avi: fix warnings]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 81dac72..5a3a032 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -26,6 +26,7 @@
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/moduleparam.h>
+#include "kvm_cache_regs.h"
#include <asm/io.h>
#include <asm/desc.h>
@@ -715,9 +716,9 @@
unsigned long rip;
u32 interruptibility;
- rip = vmcs_readl(GUEST_RIP);
+ rip = kvm_rip_read(vcpu);
rip += vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
- vmcs_writel(GUEST_RIP, rip);
+ kvm_rip_write(vcpu, rip);
/*
* We emulated an instruction, so temporary interrupt blocking
@@ -947,24 +948,19 @@
return ret;
}
-/*
- * Sync the rsp and rip registers into the vcpu structure. This allows
- * registers to be accessed by indexing vcpu->arch.regs.
- */
-static void vcpu_load_rsp_rip(struct kvm_vcpu *vcpu)
+static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
{
- vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
- vcpu->arch.rip = vmcs_readl(GUEST_RIP);
-}
-
-/*
- * Syncs rsp and rip back into the vmcs. Should be called after possible
- * modification.
- */
-static void vcpu_put_rsp_rip(struct kvm_vcpu *vcpu)
-{
- vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
- vmcs_writel(GUEST_RIP, vcpu->arch.rip);
+ __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+ switch (reg) {
+ case VCPU_REGS_RSP:
+ vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
+ break;
+ case VCPU_REGS_RIP:
+ vcpu->arch.regs[VCPU_REGS_RIP] = vmcs_readl(GUEST_RIP);
+ break;
+ default:
+ break;
+ }
}
static int set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_debug_guest *dbg)
@@ -2019,6 +2015,7 @@
u64 msr;
int ret;
+ vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP));
down_read(&vcpu->kvm->slots_lock);
if (!init_rmode(vmx->vcpu.kvm)) {
ret = -ENOMEM;
@@ -2072,10 +2069,10 @@
vmcs_writel(GUEST_RFLAGS, 0x02);
if (vmx->vcpu.vcpu_id == 0)
- vmcs_writel(GUEST_RIP, 0xfff0);
+ kvm_rip_write(vcpu, 0xfff0);
else
- vmcs_writel(GUEST_RIP, 0);
- vmcs_writel(GUEST_RSP, 0);
+ kvm_rip_write(vcpu, 0);
+ kvm_register_write(vcpu, VCPU_REGS_RSP, 0);
/* todo: dr0 = dr1 = dr2 = dr3 = 0; dr6 = 0xffff0ff0 */
vmcs_writel(GUEST_DR7, 0x400);
@@ -2139,11 +2136,11 @@
if (vcpu->arch.rmode.active) {
vmx->rmode.irq.pending = true;
vmx->rmode.irq.vector = irq;
- vmx->rmode.irq.rip = vmcs_readl(GUEST_RIP);
+ vmx->rmode.irq.rip = kvm_rip_read(vcpu);
vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
irq | INTR_TYPE_SOFT_INTR | INTR_INFO_VALID_MASK);
vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, 1);
- vmcs_writel(GUEST_RIP, vmx->rmode.irq.rip - 1);
+ kvm_rip_write(vcpu, vmx->rmode.irq.rip - 1);
return;
}
vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
@@ -2288,7 +2285,7 @@
}
error_code = 0;
- rip = vmcs_readl(GUEST_RIP);
+ rip = kvm_rip_read(vcpu);
if (intr_info & INTR_INFO_DELIVER_CODE_MASK)
error_code = vmcs_read32(VM_EXIT_INTR_ERROR_CODE);
if (is_page_fault(intr_info)) {
@@ -2386,27 +2383,25 @@
reg = (exit_qualification >> 8) & 15;
switch ((exit_qualification >> 4) & 3) {
case 0: /* mov to cr */
- KVMTRACE_3D(CR_WRITE, vcpu, (u32)cr, (u32)vcpu->arch.regs[reg],
- (u32)((u64)vcpu->arch.regs[reg] >> 32), handler);
+ KVMTRACE_3D(CR_WRITE, vcpu, (u32)cr,
+ (u32)kvm_register_read(vcpu, reg),
+ (u32)((u64)kvm_register_read(vcpu, reg) >> 32),
+ handler);
switch (cr) {
case 0:
- vcpu_load_rsp_rip(vcpu);
- kvm_set_cr0(vcpu, vcpu->arch.regs[reg]);
+ kvm_set_cr0(vcpu, kvm_register_read(vcpu, reg));
skip_emulated_instruction(vcpu);
return 1;
case 3:
- vcpu_load_rsp_rip(vcpu);
- kvm_set_cr3(vcpu, vcpu->arch.regs[reg]);
+ kvm_set_cr3(vcpu, kvm_register_read(vcpu, reg));
skip_emulated_instruction(vcpu);
return 1;
case 4:
- vcpu_load_rsp_rip(vcpu);
- kvm_set_cr4(vcpu, vcpu->arch.regs[reg]);
+ kvm_set_cr4(vcpu, kvm_register_read(vcpu, reg));
skip_emulated_instruction(vcpu);
return 1;
case 8:
- vcpu_load_rsp_rip(vcpu);
- kvm_set_cr8(vcpu, vcpu->arch.regs[reg]);
+ kvm_set_cr8(vcpu, kvm_register_read(vcpu, reg));
skip_emulated_instruction(vcpu);
if (irqchip_in_kernel(vcpu->kvm))
return 1;
@@ -2415,7 +2410,6 @@
};
break;
case 2: /* clts */
- vcpu_load_rsp_rip(vcpu);
vmx_fpu_deactivate(vcpu);
vcpu->arch.cr0 &= ~X86_CR0_TS;
vmcs_writel(CR0_READ_SHADOW, vcpu->arch.cr0);
@@ -2426,21 +2420,17 @@
case 1: /*mov from cr*/
switch (cr) {
case 3:
- vcpu_load_rsp_rip(vcpu);
- vcpu->arch.regs[reg] = vcpu->arch.cr3;
- vcpu_put_rsp_rip(vcpu);
+ kvm_register_write(vcpu, reg, vcpu->arch.cr3);
KVMTRACE_3D(CR_READ, vcpu, (u32)cr,
- (u32)vcpu->arch.regs[reg],
- (u32)((u64)vcpu->arch.regs[reg] >> 32),
+ (u32)kvm_register_read(vcpu, reg),
+ (u32)((u64)kvm_register_read(vcpu, reg) >> 32),
handler);
skip_emulated_instruction(vcpu);
return 1;
case 8:
- vcpu_load_rsp_rip(vcpu);
- vcpu->arch.regs[reg] = kvm_get_cr8(vcpu);
- vcpu_put_rsp_rip(vcpu);
+ kvm_register_write(vcpu, reg, kvm_get_cr8(vcpu));
KVMTRACE_2D(CR_READ, vcpu, (u32)cr,
- (u32)vcpu->arch.regs[reg], handler);
+ (u32)kvm_register_read(vcpu, reg), handler);
skip_emulated_instruction(vcpu);
return 1;
}
@@ -2472,7 +2462,6 @@
exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
dr = exit_qualification & 7;
reg = (exit_qualification >> 8) & 15;
- vcpu_load_rsp_rip(vcpu);
if (exit_qualification & 16) {
/* mov from dr */
switch (dr) {
@@ -2485,12 +2474,11 @@
default:
val = 0;
}
- vcpu->arch.regs[reg] = val;
+ kvm_register_write(vcpu, reg, val);
KVMTRACE_2D(DR_READ, vcpu, (u32)dr, (u32)val, handler);
} else {
/* mov to dr */
}
- vcpu_put_rsp_rip(vcpu);
skip_emulated_instruction(vcpu);
return 1;
}
@@ -2735,8 +2723,8 @@
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 vectoring_info = vmx->idt_vectoring_info;
- KVMTRACE_3D(VMEXIT, vcpu, exit_reason, (u32)vmcs_readl(GUEST_RIP),
- (u32)((u64)vmcs_readl(GUEST_RIP) >> 32), entryexit);
+ KVMTRACE_3D(VMEXIT, vcpu, exit_reason, (u32)kvm_rip_read(vcpu),
+ (u32)((u64)kvm_rip_read(vcpu) >> 32), entryexit);
/* Access CR3 don't cause VMExit in paging mode, so we need
* to sync with guest real CR3. */
@@ -2922,9 +2910,9 @@
static void fixup_rmode_irq(struct vcpu_vmx *vmx)
{
vmx->rmode.irq.pending = 0;
- if (vmcs_readl(GUEST_RIP) + 1 != vmx->rmode.irq.rip)
+ if (kvm_rip_read(&vmx->vcpu) + 1 != vmx->rmode.irq.rip)
return;
- vmcs_writel(GUEST_RIP, vmx->rmode.irq.rip);
+ kvm_rip_write(&vmx->vcpu, vmx->rmode.irq.rip);
if (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK) {
vmx->idt_vectoring_info &= ~VECTORING_INFO_TYPE_MASK;
vmx->idt_vectoring_info |= INTR_TYPE_EXT_INTR;
@@ -2941,6 +2929,11 @@
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 intr_info;
+ if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))
+ vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
+ if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
+ vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);
+
/*
* Loading guest fpu may have cleared host cr0.ts
*/
@@ -3061,6 +3054,9 @@
#endif
);
+ vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP));
+ vcpu->arch.regs_dirty = 0;
+
vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
if (vmx->rmode.irq.pending)
fixup_rmode_irq(vmx);
@@ -3224,8 +3220,7 @@
.set_idt = vmx_set_idt,
.get_gdt = vmx_get_gdt,
.set_gdt = vmx_set_gdt,
- .cache_regs = vcpu_load_rsp_rip,
- .decache_regs = vcpu_put_rsp_rip,
+ .cache_reg = vmx_cache_reg,
.get_rflags = vmx_get_rflags,
.set_rflags = vmx_set_rflags,