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-rw-r--r--drivers/kvm/kvm.h8
-rw-r--r--drivers/kvm/kvm_main.c156
-rw-r--r--drivers/kvm/svm.c19
-rw-r--r--drivers/kvm/vmx.c29
-rw-r--r--drivers/kvm/x86_emulate.c11
-rw-r--r--include/linux/kvm_para.h159
6 files changed, 199 insertions, 183 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 3b0bc4bda5f..da9c3aa1c08 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -46,6 +46,7 @@
#define KVM_MAX_CPUID_ENTRIES 40
#define DE_VECTOR 0
+#define UD_VECTOR 6
#define NM_VECTOR 7
#define DF_VECTOR 8
#define TS_VECTOR 10
@@ -317,9 +318,6 @@ struct kvm_vcpu {
unsigned long cr0;
unsigned long cr2;
unsigned long cr3;
- gpa_t para_state_gpa;
- struct page *para_state_page;
- gpa_t hypercall_gpa;
unsigned long cr4;
unsigned long cr8;
u64 pdptrs[4]; /* pae */
@@ -622,7 +620,9 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
int kvm_mmu_load(struct kvm_vcpu *vcpu);
void kvm_mmu_unload(struct kvm_vcpu *vcpu);
-int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
+
+int kvm_fix_hypercall(struct kvm_vcpu *vcpu);
static inline void kvm_guest_enter(void)
{
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index c0f372f1d76..1c662f63b7a 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -39,6 +39,7 @@
#include <linux/smp.h>
#include <linux/anon_inodes.h>
#include <linux/profile.h>
+#include <linux/kvm_para.h>
#include <asm/processor.h>
#include <asm/msr.h>
@@ -1362,51 +1363,61 @@ int kvm_emulate_halt(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt);
-int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run)
+int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
- unsigned long nr, a0, a1, a2, a3, a4, a5, ret;
+ unsigned long nr, a0, a1, a2, a3, ret;
kvm_x86_ops->cache_regs(vcpu);
- ret = -KVM_EINVAL;
-#ifdef CONFIG_X86_64
- if (is_long_mode(vcpu)) {
- nr = vcpu->regs[VCPU_REGS_RAX];
- a0 = vcpu->regs[VCPU_REGS_RDI];
- a1 = vcpu->regs[VCPU_REGS_RSI];
- a2 = vcpu->regs[VCPU_REGS_RDX];
- a3 = vcpu->regs[VCPU_REGS_RCX];
- a4 = vcpu->regs[VCPU_REGS_R8];
- a5 = vcpu->regs[VCPU_REGS_R9];
- } else
-#endif
- {
- nr = vcpu->regs[VCPU_REGS_RBX] & -1u;
- a0 = vcpu->regs[VCPU_REGS_RAX] & -1u;
- a1 = vcpu->regs[VCPU_REGS_RCX] & -1u;
- a2 = vcpu->regs[VCPU_REGS_RDX] & -1u;
- a3 = vcpu->regs[VCPU_REGS_RSI] & -1u;
- a4 = vcpu->regs[VCPU_REGS_RDI] & -1u;
- a5 = vcpu->regs[VCPU_REGS_RBP] & -1u;
+
+ nr = vcpu->regs[VCPU_REGS_RAX];
+ a0 = vcpu->regs[VCPU_REGS_RBX];
+ a1 = vcpu->regs[VCPU_REGS_RCX];
+ a2 = vcpu->regs[VCPU_REGS_RDX];
+ a3 = vcpu->regs[VCPU_REGS_RSI];
+
+ if (!is_long_mode(vcpu)) {
+ nr &= 0xFFFFFFFF;
+ a0 &= 0xFFFFFFFF;
+ a1 &= 0xFFFFFFFF;
+ a2 &= 0xFFFFFFFF;
+ a3 &= 0xFFFFFFFF;
}
+
switch (nr) {
default:
- run->hypercall.nr = nr;
- run->hypercall.args[0] = a0;
- run->hypercall.args[1] = a1;
- run->hypercall.args[2] = a2;
- run->hypercall.args[3] = a3;
- run->hypercall.args[4] = a4;
- run->hypercall.args[5] = a5;
- run->hypercall.ret = ret;
- run->hypercall.longmode = is_long_mode(vcpu);
- kvm_x86_ops->decache_regs(vcpu);
- return 0;
+ ret = -KVM_ENOSYS;
+ break;
}
vcpu->regs[VCPU_REGS_RAX] = ret;
kvm_x86_ops->decache_regs(vcpu);
- return 1;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);
+
+int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
+{
+ char instruction[3];
+ int ret = 0;
+
+ mutex_lock(&vcpu->kvm->lock);
+
+ /*
+ * Blow out the MMU to ensure that no other VCPU has an active mapping
+ * to ensure that the updated hypercall appears atomically across all
+ * VCPUs.
+ */
+ kvm_mmu_zap_all(vcpu->kvm);
+
+ kvm_x86_ops->cache_regs(vcpu);
+ kvm_x86_ops->patch_hypercall(vcpu, instruction);
+ if (emulator_write_emulated(vcpu->rip, instruction, 3, vcpu)
+ != X86EMUL_CONTINUE)
+ ret = -EFAULT;
+
+ mutex_unlock(&vcpu->kvm->lock);
+
+ return ret;
}
-EXPORT_SYMBOL_GPL(kvm_hypercall);
static u64 mk_cr_64(u64 curr_cr, u32 new_val)
{
@@ -1474,75 +1485,6 @@ void realmode_set_cr(struct kvm_vcpu *vcpu, int cr, unsigned long val,
}
}
-/*
- * Register the para guest with the host:
- */
-static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
-{
- struct kvm_vcpu_para_state *para_state;
- hpa_t para_state_hpa, hypercall_hpa;
- struct page *para_state_page;
- unsigned char *hypercall;
- gpa_t hypercall_gpa;
-
- printk(KERN_DEBUG "kvm: guest trying to enter paravirtual mode\n");
- printk(KERN_DEBUG ".... para_state_gpa: %08Lx\n", para_state_gpa);
-
- /*
- * Needs to be page aligned:
- */
- if (para_state_gpa != PAGE_ALIGN(para_state_gpa))
- goto err_gp;
-
- para_state_hpa = gpa_to_hpa(vcpu, para_state_gpa);
- printk(KERN_DEBUG ".... para_state_hpa: %08Lx\n", para_state_hpa);
- if (is_error_hpa(para_state_hpa))
- goto err_gp;
-
- mark_page_dirty(vcpu->kvm, para_state_gpa >> PAGE_SHIFT);
- para_state_page = pfn_to_page(para_state_hpa >> PAGE_SHIFT);
- para_state = kmap(para_state_page);
-
- printk(KERN_DEBUG ".... guest version: %d\n", para_state->guest_version);
- printk(KERN_DEBUG ".... size: %d\n", para_state->size);
-
- para_state->host_version = KVM_PARA_API_VERSION;
- /*
- * We cannot support guests that try to register themselves
- * with a newer API version than the host supports:
- */
- if (para_state->guest_version > KVM_PARA_API_VERSION) {
- para_state->ret = -KVM_EINVAL;
- goto err_kunmap_skip;
- }
-
- hypercall_gpa = para_state->hypercall_gpa;
- hypercall_hpa = gpa_to_hpa(vcpu, hypercall_gpa);
- printk(KERN_DEBUG ".... hypercall_hpa: %08Lx\n", hypercall_hpa);
- if (is_error_hpa(hypercall_hpa)) {
- para_state->ret = -KVM_EINVAL;
- goto err_kunmap_skip;
- }
-
- printk(KERN_DEBUG "kvm: para guest successfully registered.\n");
- vcpu->para_state_page = para_state_page;
- vcpu->para_state_gpa = para_state_gpa;
- vcpu->hypercall_gpa = hypercall_gpa;
-
- mark_page_dirty(vcpu->kvm, hypercall_gpa >> PAGE_SHIFT);
- hypercall = kmap_atomic(pfn_to_page(hypercall_hpa >> PAGE_SHIFT),
- KM_USER1) + (hypercall_hpa & ~PAGE_MASK);
- kvm_x86_ops->patch_hypercall(vcpu, hypercall);
- kunmap_atomic(hypercall, KM_USER1);
-
- para_state->ret = 0;
-err_kunmap_skip:
- kunmap(para_state_page);
- return 0;
-err_gp:
- return 1;
-}
-
int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
u64 data;
@@ -1656,12 +1598,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
case MSR_IA32_MISC_ENABLE:
vcpu->ia32_misc_enable_msr = data;
break;
- /*
- * This is the 'probe whether the host is KVM' logic:
- */
- case MSR_KVM_API_MAGIC:
- return vcpu_register_para(vcpu, data);
-
default:
pr_unimpl(vcpu, "unhandled wrmsr: 0x%x\n", msr);
return 1;
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index ced4ac1955d..794d95416f7 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -476,7 +476,8 @@ static void init_vmcb(struct vmcb *vmcb)
INTERCEPT_DR5_MASK |
INTERCEPT_DR7_MASK;
- control->intercept_exceptions = 1 << PF_VECTOR;
+ control->intercept_exceptions = (1 << PF_VECTOR) |
+ (1 << UD_VECTOR);
control->intercept = (1ULL << INTERCEPT_INTR) |
@@ -979,6 +980,17 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
return 0;
}
+static int ud_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+ int er;
+
+ er = emulate_instruction(&svm->vcpu, kvm_run, 0, 0);
+ if (er != EMULATE_DONE)
+ inject_ud(&svm->vcpu);
+
+ return 1;
+}
+
static int nm_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
svm->vmcb->control.intercept_exceptions &= ~(1 << NM_VECTOR);
@@ -1045,7 +1057,8 @@ static int vmmcall_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
svm->next_rip = svm->vmcb->save.rip + 3;
skip_emulated_instruction(&svm->vcpu);
- return kvm_hypercall(&svm->vcpu, kvm_run);
+ kvm_emulate_hypercall(&svm->vcpu);
+ return 1;
}
static int invalid_op_interception(struct vcpu_svm *svm,
@@ -1241,6 +1254,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
[SVM_EXIT_WRITE_DR3] = emulate_on_interception,
[SVM_EXIT_WRITE_DR5] = emulate_on_interception,
[SVM_EXIT_WRITE_DR7] = emulate_on_interception,
+ [SVM_EXIT_EXCP_BASE + UD_VECTOR] = ud_interception,
[SVM_EXIT_EXCP_BASE + PF_VECTOR] = pf_interception,
[SVM_EXIT_EXCP_BASE + NM_VECTOR] = nm_interception,
[SVM_EXIT_INTR] = nop_on_interception,
@@ -1675,7 +1689,6 @@ svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
hypercall[0] = 0x0f;
hypercall[1] = 0x01;
hypercall[2] = 0xd9;
- hypercall[3] = 0xc3;
}
static void svm_check_processor_compat(void *rtn)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 5b397b6c9f9..47c827d3007 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -164,6 +164,13 @@ static inline int is_no_device(u32 intr_info)
(INTR_TYPE_EXCEPTION | NM_VECTOR | INTR_INFO_VALID_MASK);
}
+static inline int is_invalid_opcode(u32 intr_info)
+{
+ return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VECTOR_MASK |
+ INTR_INFO_VALID_MASK)) ==
+ (INTR_TYPE_EXCEPTION | UD_VECTOR | INTR_INFO_VALID_MASK);
+}
+
static inline int is_external_interrupt(u32 intr_info)
{
return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK))
@@ -315,7 +322,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
{
u32 eb;
- eb = 1u << PF_VECTOR;
+ eb = (1u << PF_VECTOR) | (1u << UD_VECTOR);
if (!vcpu->fpu_active)
eb |= 1u << NM_VECTOR;
if (vcpu->guest_debug.enabled)
@@ -560,6 +567,14 @@ static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code)
INTR_INFO_VALID_MASK);
}
+static void vmx_inject_ud(struct kvm_vcpu *vcpu)
+{
+ vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
+ UD_VECTOR |
+ INTR_TYPE_EXCEPTION |
+ INTR_INFO_VALID_MASK);
+}
+
/*
* Swap MSR entry in host/guest MSR entry array.
*/
@@ -1771,6 +1786,14 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
return 1;
}
+ if (is_invalid_opcode(intr_info)) {
+ er = emulate_instruction(vcpu, kvm_run, 0, 0);
+ if (er != EMULATE_DONE)
+ vmx_inject_ud(vcpu);
+
+ return 1;
+ }
+
error_code = 0;
rip = vmcs_readl(GUEST_RIP);
if (intr_info & INTR_INFO_DELIEVER_CODE_MASK)
@@ -1873,7 +1896,6 @@ vmx_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
hypercall[0] = 0x0f;
hypercall[1] = 0x01;
hypercall[2] = 0xc1;
- hypercall[3] = 0xc3;
}
static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
@@ -2059,7 +2081,8 @@ static int handle_halt(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
static int handle_vmcall(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
skip_emulated_instruction(vcpu);
- return kvm_hypercall(vcpu, kvm_run);
+ kvm_emulate_hypercall(vcpu);
+ return 1;
}
/*
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 84af9cc737f..f12bc2c7404 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1384,7 +1384,11 @@ twobyte_insn:
if (modrm_mod != 3 || modrm_rm != 1)
goto cannot_emulate;
- /* nop */
+ rc = kvm_fix_hypercall(ctxt->vcpu);
+ if (rc)
+ goto done;
+
+ kvm_emulate_hypercall(ctxt->vcpu);
break;
case 2: /* lgdt */
rc = read_descriptor(ctxt, ops, src.ptr,
@@ -1395,7 +1399,10 @@ twobyte_insn:
break;
case 3: /* lidt/vmmcall */
if (modrm_mod == 3 && modrm_rm == 1) {
- /* nop */
+ rc = kvm_fix_hypercall(ctxt->vcpu);
+ if (rc)
+ goto done;
+ kvm_emulate_hypercall(ctxt->vcpu);
} else {
rc = read_descriptor(ctxt, ops, src.ptr,
&size, &address,
diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h
index 3b292565a69..cc5dfb43370 100644
--- a/include/linux/kvm_para.h
+++ b/include/linux/kvm_para.h
@@ -1,73 +1,110 @@
#ifndef __LINUX_KVM_PARA_H
#define __LINUX_KVM_PARA_H
-/*
- * Guest OS interface for KVM paravirtualization
- *
- * Note: this interface is totally experimental, and is certain to change
- * as we make progress.
+/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It
+ * should be used to determine that a VM is running under KVM.
*/
+#define KVM_CPUID_SIGNATURE 0x40000000
-/*
- * Per-VCPU descriptor area shared between guest and host. Writable to
- * both guest and host. Registered with the host by the guest when
- * a guest acknowledges paravirtual mode.
- *
- * NOTE: all addresses are guest-physical addresses (gpa), to make it
- * easier for the hypervisor to map between the various addresses.
- */
-struct kvm_vcpu_para_state {
- /*
- * API version information for compatibility. If there's any support
- * mismatch (too old host trying to execute too new guest) then
- * the host will deny entry into paravirtual mode. Any other
- * combination (new host + old guest and new host + new guest)
- * is supposed to work - new host versions will support all old
- * guest API versions.
- */
- u32 guest_version;
- u32 host_version;
- u32 size;
- u32 ret;
-
- /*
- * The address of the vm exit instruction (VMCALL or VMMCALL),
- * which the host will patch according to the CPU model the
- * VM runs on:
- */
- u64 hypercall_gpa;
-
-} __attribute__ ((aligned(PAGE_SIZE)));
-
-#define KVM_PARA_API_VERSION 1
-
-/*
- * This is used for an RDMSR's ECX parameter to probe for a KVM host.
- * Hopefully no CPU vendor will use up this number. This is placed well
- * out of way of the typical space occupied by CPU vendors' MSR indices,
- * and we think (or at least hope) it wont be occupied in the future
- * either.
+/* This CPUID returns a feature bitmap in eax. Before enabling a particular
+ * paravirtualization, the appropriate feature bit should be checked.
*/
-#define MSR_KVM_API_MAGIC 0x87655678
+#define KVM_CPUID_FEATURES 0x40000001
-#define KVM_EINVAL 1
+/* Return values for hypercalls */
+#define KVM_ENOSYS 1000
-/*
- * Hypercall calling convention:
- *
- * Each hypercall may have 0-6 parameters.
- *
- * 64-bit hypercall index is in RAX, goes from 0 to __NR_hypercalls-1
- *
- * 64-bit parameters 1-6 are in the standard gcc x86_64 calling convention
- * order: RDI, RSI, RDX, RCX, R8, R9.
- *
- * 32-bit index is EBX, parameters are: EAX, ECX, EDX, ESI, EDI, EBP.
- * (the first 3 are according to the gcc regparm calling convention)
+#ifdef __KERNEL__
+#include <asm/processor.h>
+
+/* This instruction is vmcall. On non-VT architectures, it will generate a
+ * trap that we will then rewrite to the appropriate instruction.
+ */
+#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
+
+/* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
+ * instruction. The hypervisor may replace it with something else but only the
+ * instructions are guaranteed to be supported.
*
- * No registers are clobbered by the hypercall, except that the
- * return value is in RAX.
+ * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
+ * The hypercall number should be placed in rax and the return value will be
+ * placed in rax. No other registers will be clobbered unless explicited
+ * noted by the particular hypercall.
*/
-#define __NR_hypercalls 0
+
+static inline long kvm_hypercall0(unsigned int nr)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr));
+ return ret;
+}
+
+static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1));
+ return ret;
+}
+
+static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
+ unsigned long p2)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2));
+ return ret;
+}
+
+static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
+ unsigned long p2, unsigned long p3)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2), "d"(p3));
+ return ret;
+}
+
+static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
+ unsigned long p2, unsigned long p3,
+ unsigned long p4)
+{
+ long ret;
+ asm volatile(KVM_HYPERCALL
+ : "=a"(ret)
+ : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4));
+ return ret;
+}
+
+static inline int kvm_para_available(void)
+{
+ unsigned int eax, ebx, ecx, edx;
+ char signature[13];
+
+ cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
+ memcpy(signature + 0, &ebx, 4);
+ memcpy(signature + 4, &ecx, 4);
+ memcpy(signature + 8, &edx, 4);
+ signature[12] = 0;
+
+ if (strcmp(signature, "KVMKVMKVM") == 0)
+ return 1;
+
+ return 0;
+}
+
+static inline int kvm_para_has_feature(unsigned int feature)
+{
+ if (cpuid_eax(KVM_CPUID_FEATURES) & (1UL << feature))
+ return 1;
+ return 0;
+}
+
+#endif
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-07 06:55:53 +0000