[PATCH -v3] KVM: MCE: Add MCE support to KVM

Huang Ying
2009-05-11T08:49:31Z

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The related MSRs are emulated. MCE capability is exported via
extension KVM_CAP_MCE and ioctl KVM_X86_GET_MCE_CAP_SUPPORTED. A new
vcpu ioctl command KVM_X86_SETUP_MCE is used to setup MCE emulation
such as the mcg_cap. MCE is injected via vcpu ioctl command
KVM_X86_SET_MCE. Extended machine-check state (MCG_EXT_P) and CMCI are
not implemented.

ChangeLog:

v3:

- Fix KVM_CAP_MCE declaration

v2:

- Add MCE capability exportation support.
- Allocate MCE banks registers simulation backing memory during VCPU
initialization.

Signed-off-by: Huang Ying <ying.huang@intel.com>

---
arch/x86/include/asm/kvm.h | 1
arch/x86/include/asm/kvm_host.h | 5
arch/x86/kvm/x86.c | 220 +++++++++++++++++++++++++++++++++++-----
include/linux/kvm.h | 21 +++
4 files changed, 223 insertions(+), 24 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -42,6 +42,7 @@
#include <asm/msr.h>
#include <asm/desc.h>
#include <asm/mtrr.h>
+#include <asm/mce.h>

#define MAX_IO_MSRS 256
#define CR0_RESERVED_BITS \
@@ -55,6 +56,10 @@
| X86_CR4_OSXMMEXCPT | X86_CR4_VMXE))

#define CR8_RESERVED_BITS (~(unsigned long)X86_CR8_TPR)
+
+#define KVM_MAX_MCE_BANKS 32
+#define KVM_MCE_CAP_SUPPORTED MCG_CTL_P
+
/* EFER defaults:
* - enable syscall per default because its emulated by KVM
* - enable LME and LMA per default on 64 bit KVM
@@ -737,23 +742,43 @@ static int set_msr_mtrr(struct kvm_vcpu
return 0;
}

-int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+static int set_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
+ u64 mcg_cap = vcpu->arch.mcg_cap;
+ unsigned bank_num = mcg_cap & 0xff;
+
switch (msr) {
- case MSR_EFER:
- set_efer(vcpu, data);
- break;
- case MSR_IA32_MC0_STATUS:
- pr_unimpl(vcpu, "%s: MSR_IA32_MC0_STATUS 0x%llx, nop\n",
- __func__, data);
- break;
case MSR_IA32_MCG_STATUS:
- pr_unimpl(vcpu, "%s: MSR_IA32_MCG_STATUS 0x%llx, nop\n",
- __func__, data);
+ vcpu->arch.mcg_status = data;
break;
case MSR_IA32_MCG_CTL:
- pr_unimpl(vcpu, "%s: MSR_IA32_MCG_CTL 0x%llx, nop\n",
- __func__, data);
+ if (!(mcg_cap & MCG_CTL_P))
+ return 1;
+ if (data != 0 && data != ~(u64)0)
+ return -1;
+ vcpu->arch.mcg_ctl = data;
+ break;
+ default:
+ if (msr >= MSR_IA32_MC0_CTL &&
+ msr < MSR_IA32_MC0_CTL + 4 * bank_num) {
+ u32 offset = msr - MSR_IA32_MC0_CTL;
+ /* only 0 or all 1s can be written to IA32_MCi_CTL */
+ if ((offset & 0x3) == 0 &&
+ data != 0 && data != ~(u64)0)
+ return -1;
+ vcpu->arch.mce_banks[offset] = data;
+ break;
+ }
+ return 1;
+ }
+ return 0;
+}
+
+int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+ switch (msr) {
+ case MSR_EFER:
+ set_efer(vcpu, data);
break;
case MSR_IA32_DEBUGCTLMSR:
if (!data) {
@@ -809,6 +834,10 @@ int kvm_set_msr_common(struct kvm_vcpu *
kvm_request_guest_time_update(vcpu);
break;
}
+ case MSR_IA32_MCG_CTL:
+ case MSR_IA32_MCG_STATUS:
+ case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
+ return set_msr_mce(vcpu, msr, data);
default:
pr_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n", msr, data);
return 1;
@@ -864,26 +893,49 @@ static int get_msr_mtrr(struct kvm_vcpu
return 0;
}

-int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
{
u64 data;
+ u64 mcg_cap = vcpu->arch.mcg_cap;
+ unsigned bank_num = mcg_cap & 0xff;

switch (msr) {
- case 0xc0010010: /* SYSCFG */
- case 0xc0010015: /* HWCR */
- case MSR_IA32_PLATFORM_ID:
case MSR_IA32_P5_MC_ADDR:
case MSR_IA32_P5_MC_TYPE:
- case MSR_IA32_MC0_CTL:
- case MSR_IA32_MCG_STATUS:
+ data = 0;
+ break;
case MSR_IA32_MCG_CAP:
+ data = vcpu->arch.mcg_cap;
+ break;
case MSR_IA32_MCG_CTL:
- case MSR_IA32_MC0_MISC:
- case MSR_IA32_MC0_MISC+4:
- case MSR_IA32_MC0_MISC+8:
- case MSR_IA32_MC0_MISC+12:
- case MSR_IA32_MC0_MISC+16:
- case MSR_IA32_MC0_MISC+20:
+ if (!(mcg_cap & MCG_CTL_P))
+ return 1;
+ data = vcpu->arch.mcg_ctl;
+ break;
+ case MSR_IA32_MCG_STATUS:
+ data = vcpu->arch.mcg_status;
+ break;
+ default:
+ if (msr >= MSR_IA32_MC0_CTL &&
+ msr < MSR_IA32_MC0_CTL + 4 * bank_num) {
+ u32 offset = msr - MSR_IA32_MC0_CTL;
+ data = vcpu->arch.mce_banks[offset];
+ break;
+ }
+ return 1;
+ }
+ *pdata = data;
+ return 0;
+}
+
+int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+{
+ u64 data;
+
+ switch (msr) {
+ case 0xc0010010: /* SYSCFG */
+ case 0xc0010015: /* HWCR */
+ case MSR_IA32_PLATFORM_ID:
case MSR_IA32_UCODE_REV:
case MSR_IA32_EBL_CR_POWERON:
case MSR_IA32_DEBUGCTLMSR:
@@ -925,6 +977,13 @@ int kvm_get_msr_common(struct kvm_vcpu *
case MSR_KVM_SYSTEM_TIME:
data = vcpu->arch.time;
break;
+ case MSR_IA32_P5_MC_ADDR:
+ case MSR_IA32_P5_MC_TYPE:
+ case MSR_IA32_MCG_CAP:
+ case MSR_IA32_MCG_CTL:
+ case MSR_IA32_MCG_STATUS:
+ case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1:
+ return get_msr_mce(vcpu, msr, pdata);
default:
pr_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr);
return 1;
@@ -1046,6 +1105,9 @@ int kvm_dev_ioctl_check_extension(long e
case KVM_CAP_IOMMU:
r = iommu_found();
break;
+ case KVM_CAP_MCE:
+ r = KVM_MAX_MCE_BANKS;
+ break;
default:
r = 0;
break;
@@ -1106,6 +1168,16 @@ long kvm_arch_dev_ioctl(struct file *fil
r = 0;
break;
}
+ case KVM_X86_GET_MCE_CAP_SUPPORTED: {
+ u64 mce_cap;
+
+ mce_cap = KVM_MCE_CAP_SUPPORTED;
+ r = -EFAULT;
+ if (copy_to_user(argp, &mce_cap, sizeof mce_cap))
+ goto out;
+ r = 0;
+ break;
+ }
default:
r = -EINVAL;
}
@@ -1463,6 +1535,80 @@ static int vcpu_ioctl_tpr_access_reporti
return 0;
}

+static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
+ u64 mcg_cap)
+{
+ int r;
+ unsigned bank_num = mcg_cap & 0xff, bank;
+
+ r = -EINVAL;
+ if (!bank_num)
+ goto out;
+ if (mcg_cap & ~(KVM_MCE_CAP_SUPPORTED | 0xff | 0xff0000))
+ goto out;
+ r = 0;
+ vcpu->arch.mcg_cap = mcg_cap;
+ /* Init IA32_MCG_CTL to all 1s */
+ if (mcg_cap & MCG_CTL_P)
+ vcpu->arch.mcg_ctl = ~(u64)0;
+ /* Init IA32_MCi_CTL to all 1s */
+ for (bank = 0; bank < bank_num; bank++)
+ vcpu->arch.mce_banks[bank*4] = ~(u64)0;
+out:
+ return r;
+}
+
+static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
+ struct kvm_x86_mce *mce)
+{
+ u64 mcg_cap = vcpu->arch.mcg_cap;
+ unsigned bank_num = mcg_cap & 0xff;
+ u64 *banks = vcpu->arch.mce_banks;
+
+ if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
+ return -EINVAL;
+ /*
+ * if IA32_MCG_CTL is not all 1s, the uncorrected error
+ * reporting is disabled
+ */
+ if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
+ vcpu->arch.mcg_ctl != ~(u64)0)
+ return 0;
+ banks += 4 * mce->bank;
+ /*
+ * if IA32_MCi_CTL is not all 1s, the uncorrected error
+ * reporting is disabled for the bank
+ */
+ if ((mce->status & MCI_STATUS_UC) && banks[0] != ~(u64)0)
+ return 0;
+ if (mce->status & MCI_STATUS_UC) {
+ if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
+ !(vcpu->arch.cr4 & X86_CR4_MCE)) {
+ printk(KERN_DEBUG "kvm: set_mce: "
+ "injects mce exception while "
+ "previous one is in progress!\n");
+ set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
+ return 0;
+ }
+ if (banks[1] & MCI_STATUS_VAL)
+ mce->status |= MCI_STATUS_OVER;
+ banks[2] = mce->addr;
+ banks[3] = mce->misc;
+ vcpu->arch.mcg_status = mce->mcg_status;
+ banks[1] = mce->status;
+ kvm_queue_exception(vcpu, MC_VECTOR);
+ } else if (!(banks[1] & MCI_STATUS_VAL)
+ || !(banks[1] & MCI_STATUS_UC)) {
+ if (banks[1] & MCI_STATUS_VAL)
+ mce->status |= MCI_STATUS_OVER;
+ banks[2] = mce->addr;
+ banks[3] = mce->misc;
+ banks[1] = mce->status;
+ } else
+ banks[1] |= MCI_STATUS_OVER;
+ return 0;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -1596,6 +1742,24 @@ long kvm_arch_vcpu_ioctl(struct file *fi
kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
break;
}
+ case KVM_X86_SETUP_MCE: {
+ u64 mcg_cap;
+
+ r = -EFAULT;
+ if (copy_from_user(&mcg_cap, argp, sizeof mcg_cap))
+ goto out;
+ r = kvm_vcpu_ioctl_x86_setup_mce(vcpu, mcg_cap);
+ break;
+ }
+ case KVM_X86_SET_MCE: {
+ struct kvm_x86_mce mce;
+
+ r = -EFAULT;
+ if (copy_from_user(&mce, argp, sizeof mce))
+ goto out;
+ r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
+ break;
+ }
default:
r = -EINVAL;
}
@@ -4411,6 +4575,14 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *
goto fail_mmu_destroy;
}

+ vcpu->arch.mce_banks = kzalloc(KVM_MAX_MCE_BANKS * sizeof(u64) * 4,
+ GFP_KERNEL);
+ if (!vcpu->arch.mce_banks) {
+ r = -ENOMEM;
+ goto fail_mmu_destroy;
+ }
+ vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
+
return 0;

fail_mmu_destroy:
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -371,6 +371,11 @@ struct kvm_vcpu_arch {
unsigned long dr6;
unsigned long dr7;
unsigned long eff_db[KVM_NR_DB_REGS];
+
+ u64 mcg_cap;
+ u64 mcg_status;
+ u64 mcg_ctl;
+ u64 *mce_banks;
};

struct kvm_mem_alias {
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -415,6 +415,9 @@ struct kvm_trace_rec {
#define KVM_CAP_ASSIGN_DEV_IRQ 29
/* Another bug in KVM_SET_USER_MEMORY_REGION fixed: */
#define KVM_CAP_JOIN_MEMORY_REGIONS_WORKS 30
+#ifdef __KVM_HAVE_MCE
+#define KVM_CAP_MCE 31
+#endif

#ifdef KVM_CAP_IRQ_ROUTING

@@ -454,6 +457,20 @@ struct kvm_irq_routing {

#endif

+#ifdef KVM_CAP_MCE
+/* x86 MCE */
+struct kvm_x86_mce {
+ __u64 status;
+ __u64 addr;
+ __u64 misc;
+ __u64 mcg_status;
+ __u8 bank;
+ __u8 pad1;
+ __u16 pad2;
+ __u32 pad3;
+};
+#endif
+
/*
* ioctls for VM fds
*/
@@ -541,6 +558,10 @@ struct kvm_irq_routing {
#define KVM_NMI _IO(KVMIO, 0x9a)
/* Available with KVM_CAP_SET_GUEST_DEBUG */
#define KVM_SET_GUEST_DEBUG _IOW(KVMIO, 0x9b, struct kvm_guest_debug)
+/* MCE for x86 */
+#define KVM_X86_SETUP_MCE _IOW(KVMIO, 0x9c, __u64)
+#define KVM_X86_GET_MCE_CAP_SUPPORTED _IOR(KVMIO, 0x9d, __u64)
+#define KVM_X86_SET_MCE _IOW(KVMIO, 0x9e, struct kvm_x86_mce)

/*
* Deprecated interfaces
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -17,6 +17,7 @@
#define __KVM_HAVE_USER_NMI
#define __KVM_HAVE_GUEST_DEBUG
#define __KVM_HAVE_MSIX
+#define __KVM_HAVE_MCE

/* Architectural interrupt line count. */
#define KVM_NR_INTERRUPTS 256

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