From: Mihai Donțu <mdo...@bitdefender.com>
These are needed by the introspection subsystem.
CC: Sean Christopherson <sean.j.christopher...@intel.com>
CC: Joerg Roedel <j...@8bytes.org>
Signed-off-by: Mihai Donțu <mdo...@bitdefender.com>
Signed-off-by: Adalbert Lazăr <ala...@bitdefender.com>
---
arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/kvm/emulate.c | 10 +++++-
arch/x86/kvm/mmu.c | 37 ++++++++++++++-------
arch/x86/kvm/x86.c | 52 ++++++++++++++++++++++++------
4 files changed, 79 insertions(+), 21 deletions(-)
diff --git a/arch/x86/include/asm/kvm_emulate.h
b/arch/x86/include/asm/kvm_emulate.h
index 93c4bf598fb0..97cb592687cb 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -444,6 +444,7 @@ bool x86_page_table_writing_insn(struct x86_emulate_ctxt
*ctxt);
#define EMULATION_OK 0
#define EMULATION_RESTART 1
#define EMULATION_INTERCEPTED 2
+#define EMULATION_RETRY_INSTR 3
void init_decode_cache(struct x86_emulate_ctxt *ctxt);
int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c338984c850d..34431cf31f74 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5366,7 +5366,12 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void
*insn, int insn_len)
ctxt->memopp->addr.mem.ea + ctxt->_eip);
done:
- return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
+ if (rc == X86EMUL_RETRY_INSTR)
+ return EMULATION_RETRY_INSTR;
+ else if (rc == X86EMUL_CONTINUE)
+ return EMULATION_OK;
+ else
+ return EMULATION_FAILED;
}
bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt)
@@ -5736,6 +5741,9 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
if (rc == X86EMUL_INTERCEPTED)
return EMULATION_INTERCEPTED;
+ if (rc == X86EMUL_RETRY_INSTR)
+ return EMULATION_RETRY_INSTR;
+
if (rc == X86EMUL_CONTINUE)
writeback_registers(ctxt);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a86b165cf6dd..ff053f17b8c2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1111,9 +1111,13 @@ static void account_shadowed(struct kvm *kvm, struct
kvm_mmu_page *sp)
slot = __gfn_to_memslot(slots, gfn);
/* the non-leaf shadow pages are keeping readonly. */
- if (sp->role.level > PT_PAGE_TABLE_LEVEL)
- return kvm_slot_page_track_add_page(kvm, slot, gfn,
- KVM_PAGE_TRACK_WRITE);
+ if (sp->role.level > PT_PAGE_TABLE_LEVEL) {
+ kvm_slot_page_track_add_page(kvm, slot, gfn,
+ KVM_PAGE_TRACK_PREWRITE);
+ kvm_slot_page_track_add_page(kvm, slot, gfn,
+ KVM_PAGE_TRACK_WRITE);
+ return;
+ }
kvm_mmu_gfn_disallow_lpage(slot, gfn);
}
@@ -1128,9 +1132,13 @@ static void unaccount_shadowed(struct kvm *kvm, struct
kvm_mmu_page *sp)
gfn = sp->gfn;
slots = kvm_memslots_for_spte_role(kvm, sp->role);
slot = __gfn_to_memslot(slots, gfn);
- if (sp->role.level > PT_PAGE_TABLE_LEVEL)
- return kvm_slot_page_track_remove_page(kvm, slot, gfn,
- KVM_PAGE_TRACK_WRITE);
+ if (sp->role.level > PT_PAGE_TABLE_LEVEL) {
+ kvm_slot_page_track_remove_page(kvm, slot, gfn,
+ KVM_PAGE_TRACK_PREWRITE);
+ kvm_slot_page_track_remove_page(kvm, slot, gfn,
+ KVM_PAGE_TRACK_WRITE);
+ return;
+ }
kvm_mmu_gfn_allow_lpage(slot, gfn);
}
@@ -2884,7 +2892,8 @@ static bool mmu_need_write_protect(struct kvm_vcpu *vcpu,
gfn_t gfn,
{
struct kvm_mmu_page *sp;
- if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+ if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREWRITE) ||
+ kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
return true;
for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn) {
@@ -4006,15 +4015,21 @@ static bool page_fault_handle_page_track(struct
kvm_vcpu *vcpu,
if (unlikely(error_code & PFERR_RSVD_MASK))
return false;
- if (!(error_code & PFERR_PRESENT_MASK) ||
- !(error_code & PFERR_WRITE_MASK))
+ if (!(error_code & PFERR_PRESENT_MASK))
return false;
/*
- * guest is writing the page which is write tracked which can
+ * guest is reading/writing/fetching the page which is
+ * read/write/execute tracked which can
* not be fixed by page fault handler.
*/
- if (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE))
+ if (((error_code & PFERR_USER_MASK)
+ && kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREREAD))
+ || ((error_code & PFERR_WRITE_MASK)
+ && (kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREWRITE)
+ || kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_WRITE)))
+ || ((error_code & PFERR_FETCH_MASK)
+ && kvm_page_track_is_active(vcpu, gfn, KVM_PAGE_TRACK_PREEXEC)))
return true;
return false;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d3d159986243..7aef002be551 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5065,6 +5065,7 @@ static int kvm_read_guest_virt_helper(gva_t addr, void
*val, unsigned int bytes,
{
void *data = val;
int r = X86EMUL_CONTINUE;
+ bool data_ready;
while (bytes) {
gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access,
@@ -5075,6 +5076,13 @@ static int kvm_read_guest_virt_helper(gva_t addr, void
*val, unsigned int bytes,
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
+ if (!kvm_page_track_preread(vcpu, gpa, addr, data, toread,
+ &data_ready))
+ return X86EMUL_RETRY_INSTR;
+ if (data_ready) {
+ WARN_ON(toread > bytes); /* TODO */
+ return X86EMUL_CONTINUE;
+ }
ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, data,
offset, toread);
if (ret < 0) {
@@ -5106,6 +5114,9 @@ static int kvm_fetch_guest_virt(struct x86_emulate_ctxt
*ctxt,
if (unlikely(gpa == UNMAPPED_GVA))
return X86EMUL_PROPAGATE_FAULT;
+ if (!kvm_page_track_preexec(vcpu, gpa, addr))
+ return X86EMUL_RETRY_INSTR;
+
offset = addr & (PAGE_SIZE-1);
if (WARN_ON(offset + bytes > PAGE_SIZE))
bytes = (unsigned)PAGE_SIZE - offset;
@@ -5284,13 +5295,26 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu,
unsigned long gva,
int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
const void *val, int bytes)
{
- int ret;
-
- ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
- if (ret < 0)
- return 0;
+ if (!kvm_page_track_prewrite(vcpu, gpa, gva, val, bytes))
+ return X86EMUL_RETRY_INSTR;
+ if (kvm_vcpu_write_guest(vcpu, gpa, val, bytes) < 0)
+ return X86EMUL_UNHANDLEABLE;
kvm_page_track_write(vcpu, gpa, gva, val, bytes);
- return 1;
+ return X86EMUL_CONTINUE;
+}
+
+static int emulator_read_phys(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
+ void *val, int bytes)
+{
+ bool data_ready;
+
+ if (!kvm_page_track_preread(vcpu, gpa, gva, val, bytes, &data_ready))
+ return X86EMUL_RETRY_INSTR;
+ if (data_ready)
+ return X86EMUL_CONTINUE;
+ if (kvm_vcpu_read_guest(vcpu, gpa, val, bytes) < 0)
+ return X86EMUL_UNHANDLEABLE;
+ return X86EMUL_CONTINUE;
}
struct read_write_emulator_ops {
@@ -5320,7 +5344,7 @@ static int read_prepare(struct kvm_vcpu *vcpu, void *val,
int bytes)
static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
void *val, int bytes)
{
- return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
+ return emulator_read_phys(vcpu, gpa, gva, val, bytes);
}
static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, gva_t gva,
@@ -5395,8 +5419,11 @@ static int emulator_read_write_onepage(unsigned long
addr, void *val,
return X86EMUL_PROPAGATE_FAULT;
}
- if (!ret && ops->read_write_emulate(vcpu, gpa, addr, val, bytes))
- return X86EMUL_CONTINUE;
+ if (!ret) {
+ ret = ops->read_write_emulate(vcpu, gpa, addr, val, bytes);
+ if (ret == X86EMUL_CONTINUE || ret == X86EMUL_RETRY_INSTR)
+ return ret;
+ }
/*
* Is this MMIO handled locally?
@@ -5531,6 +5558,9 @@ static int emulator_cmpxchg_emulated(struct
x86_emulate_ctxt *ctxt,
if (is_error_page(page))
goto emul_write;
+ if (!kvm_page_track_prewrite(vcpu, gpa, addr, new, bytes))
+ return X86EMUL_RETRY_INSTR;
+
kaddr = kmap_atomic(page);
kaddr += offset_in_page(gpa);
switch (bytes) {
@@ -6416,6 +6446,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
trace_kvm_emulate_insn_start(vcpu);
++vcpu->stat.insn_emulation;
+ if (r == EMULATION_RETRY_INSTR)
+ return EMULATE_DONE;
if (r != EMULATION_OK) {
if (emulation_type & EMULTYPE_TRAP_UD)
return EMULATE_FAIL;
@@ -6457,6 +6489,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
r = x86_emulate_insn(ctxt);
+ if (r == EMULATION_RETRY_INSTR)
+ return EMULATE_DONE;
if (r == EMULATION_INTERCEPTED)
return EMULATE_DONE;
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