[PATCH v2 7/8] KVM: x86: Add helpers to test/mark reg availability and dirtiness

From: Sean Christopherson
Date: Fri Sep 27 2019 - 17:45:48 EST


Add helpers to prettify code that tests and/or marks whether or not a
register is available and/or dirty.

Suggested-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/kvm_cache_regs.h | 45 +++++++++++++++++++++++++----------
arch/x86/kvm/vmx/nested.c | 4 ++--
arch/x86/kvm/vmx/vmx.c | 29 ++++++++++------------
arch/x86/kvm/x86.c | 13 ++++------
4 files changed, 53 insertions(+), 38 deletions(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index b85fc4b4e04f..9c2bc528800b 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -37,12 +37,37 @@ BUILD_KVM_GPR_ACCESSORS(r14, R14)
BUILD_KVM_GPR_ACCESSORS(r15, R15)
#endif

+static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
+ enum kvm_reg reg)
+{
+ return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
+ enum kvm_reg reg)
+{
+ return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
+static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
+ enum kvm_reg reg)
+{
+ __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
+ enum kvm_reg reg)
+{
+ __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+ __set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
static inline unsigned long kvm_register_read(struct kvm_vcpu *vcpu, int reg)
{
if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
return 0;

- if (!test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, reg))
kvm_x86_ops->cache_reg(vcpu, reg);

return vcpu->arch.regs[reg];
@@ -55,13 +80,12 @@ static inline void kvm_register_write(struct kvm_vcpu *vcpu, int reg,
return;

vcpu->arch.regs[reg] = val;
- __set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
- __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+ kvm_register_mark_dirty(vcpu, reg);
}

static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
{
- if (!test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_REGS_RIP))
kvm_x86_ops->cache_reg(vcpu, VCPU_REGS_RIP);

return vcpu->arch.regs[VCPU_REGS_RIP];
@@ -70,13 +94,12 @@ static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val)
{
vcpu->arch.regs[VCPU_REGS_RIP] = val;
- __set_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty);
- __set_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_avail);
+ kvm_register_mark_dirty(vcpu, VCPU_REGS_RIP);
}

static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
{
- if (!test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_REGS_RSP))
kvm_x86_ops->cache_reg(vcpu, VCPU_REGS_RSP);

return vcpu->arch.regs[VCPU_REGS_RSP];
@@ -85,16 +108,14 @@ static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val)
{
vcpu->arch.regs[VCPU_REGS_RSP] = val;
- __set_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty);
- __set_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_avail);
+ kvm_register_mark_dirty(vcpu, VCPU_REGS_RSP);
}

static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
{
might_sleep(); /* on svm */

- if (!test_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
kvm_x86_ops->cache_reg(vcpu, VCPU_EXREG_PDPTR);

return vcpu->arch.walk_mmu->pdptrs[index];
@@ -123,7 +144,7 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)

static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
{
- if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
kvm_x86_ops->decache_cr3(vcpu);
return vcpu->arch.cr3;
}
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index b72a00b53e4a..8946f11c574c 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1012,7 +1012,7 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
kvm_mmu_new_cr3(vcpu, cr3, false);

vcpu->arch.cr3 = cr3;
- __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);

kvm_init_mmu(vcpu, false);

@@ -3986,7 +3986,7 @@ static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu)

nested_ept_uninit_mmu_context(vcpu);
vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
- __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);

/*
* Use ept_save_pdptrs(vcpu) to load the MMU's cached PDPTRs
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 814d3e6d0264..ed03d0cd1cc8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -721,8 +721,8 @@ static bool vmx_segment_cache_test_set(struct vcpu_vmx *vmx, unsigned seg,
bool ret;
u32 mask = 1 << (seg * SEG_FIELD_NR + field);

- if (!(vmx->vcpu.arch.regs_avail & (1 << VCPU_EXREG_SEGMENTS))) {
- vmx->vcpu.arch.regs_avail |= (1 << VCPU_EXREG_SEGMENTS);
+ if (!kvm_register_is_available(&vmx->vcpu, VCPU_EXREG_SEGMENTS)) {
+ kvm_register_mark_available(&vmx->vcpu, VCPU_EXREG_SEGMENTS);
vmx->segment_cache.bitmask = 0;
}
ret = vmx->segment_cache.bitmask & mask;
@@ -1410,8 +1410,8 @@ unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long rflags, save_rflags;

- if (!test_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail)) {
- __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_RFLAGS)) {
+ kvm_register_mark_available(vcpu, VCPU_EXREG_RFLAGS);
rflags = vmcs_readl(GUEST_RFLAGS);
if (vmx->rmode.vm86_active) {
rflags &= RMODE_GUEST_OWNED_EFLAGS_BITS;
@@ -1429,7 +1429,7 @@ void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
unsigned long old_rflags;

if (enable_unrestricted_guest) {
- __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_RFLAGS);

vmx->rflags = rflags;
vmcs_writel(GUEST_RFLAGS, rflags);
@@ -2175,7 +2175,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)

static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
{
- __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, reg);
+
switch (reg) {
case VCPU_REGS_RSP:
vcpu->arch.regs[VCPU_REGS_RSP] = vmcs_readl(GUEST_RSP);
@@ -2862,7 +2863,7 @@ static void vmx_decache_cr3(struct kvm_vcpu *vcpu)
{
if (enable_unrestricted_guest || (enable_ept && is_paging(vcpu)))
vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
- __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);
}

static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
@@ -2877,8 +2878,7 @@ static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

- if (!test_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_dirty))
+ if (!kvm_register_is_dirty(vcpu, VCPU_EXREG_PDPTR))
return;

if (is_pae_paging(vcpu)) {
@@ -2900,10 +2900,7 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu)
mmu->pdptrs[3] = vmcs_read64(GUEST_PDPTR3);
}

- __set_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_avail);
- __set_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_dirty);
+ kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
}

static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
@@ -2912,7 +2909,7 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
{
struct vcpu_vmx *vmx = to_vmx(vcpu);

- if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
vmx_decache_cr3(vcpu);
if (!(cr0 & X86_CR0_PG)) {
/* From paging/starting to nonpaging */
@@ -6528,9 +6525,9 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (vmx->nested.need_vmcs12_to_shadow_sync)
nested_sync_vmcs12_to_shadow(vcpu);

- if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty))
+ if (kvm_register_is_dirty(vcpu, VCPU_REGS_RSP))
vmcs_writel(GUEST_RSP, vcpu->arch.regs[VCPU_REGS_RSP]);
- if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
+ if (kvm_register_is_dirty(vcpu, VCPU_REGS_RIP))
vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);

cr3 = __get_current_cr3_fast();
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0ed07d8d2caa..cd6bd7991c39 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -709,10 +709,8 @@ int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
ret = 1;

memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
- __set_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_avail);
- __set_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_dirty);
+ kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
+
out:

return ret;
@@ -730,8 +728,7 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu)
if (!is_pae_paging(vcpu))
return false;

- if (!test_bit(VCPU_EXREG_PDPTR,
- (unsigned long *)&vcpu->arch.regs_avail))
+ if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
return true;

gfn = (kvm_read_cr3(vcpu) & 0xffffffe0ul) >> PAGE_SHIFT;
@@ -976,7 +973,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)

kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush);
vcpu->arch.cr3 = cr3;
- __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);

return 0;
}
@@ -8766,7 +8763,7 @@ static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
vcpu->arch.cr2 = sregs->cr2;
mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3;
vcpu->arch.cr3 = sregs->cr3;
- __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+ kvm_register_mark_available(vcpu, VCPU_EXREG_CR3);

kvm_set_cr8(vcpu, sregs->cr8);

--
2.22.0