The current implementation only fills MC MSRs on vcpu0 and leaves MC
MSRs on other vcpus empty in the broadcast case. When guest reads 0
from MSR_IA32_MCG_STATUS on vcpuN (N > 0), it may think it's not
possible to recover the execution on that vcpu and then get panic,
although MSR_IA32_MCG_STATUS filled on vcpu0 may imply the injected
vMCE is actually recoverable. To avoid such unnecessary guest panic,
set MSR_IA32_MCG_STATUS on vcpuN (N > 0) to MCG_STATUS_MCIP|MCG_STATUS_RIPV.
In addition, fill_vmsr_data(mc_bank, ...) is changed to return -EINVAL
rather than 0, if an invalid domain ID is contained in mc_bank.
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
---
Cc: Christoph Egger <cheg...@amazon.de>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Andrew Cooper <andrew.coop...@citrix.com>
---
xen/arch/x86/cpu/mcheck/mcaction.c | 16 ++++-----
xen/arch/x86/cpu/mcheck/vmce.c | 74 ++++++++++++++++++++++++++------------
xen/arch/x86/cpu/mcheck/vmce.h | 2 +-
3 files changed, 60 insertions(+), 32 deletions(-)
diff --git a/xen/arch/x86/cpu/mcheck/mcaction.c
b/xen/arch/x86/cpu/mcheck/mcaction.c
index 32056f2..dab9eac 100644
--- a/xen/arch/x86/cpu/mcheck/mcaction.c
+++ b/xen/arch/x86/cpu/mcheck/mcaction.c
@@ -88,22 +88,22 @@ mc_memerr_dhandler(struct mca_binfo *binfo,
goto vmce_failed;
}
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ||
+ global->mc_vcpuid == XEN_MC_VCPUID_INVALID)
+ vmce_vcpuid = VMCE_INJECT_BROADCAST;
+ else
+ vmce_vcpuid = global->mc_vcpuid;
+
bank->mc_addr = gfn << PAGE_SHIFT |
(bank->mc_addr & (PAGE_SIZE -1 ));
- if ( fill_vmsr_data(bank, d,
- global->mc_gstatus) == -1 )
+ if (fill_vmsr_data(bank, d, global->mc_gstatus,
+ vmce_vcpuid == VMCE_INJECT_BROADCAST))
{
mce_printk(MCE_QUIET, "Fill vMCE# data for DOM%d "
"failed\n", bank->mc_domid);
goto vmce_failed;
}
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ||
- global->mc_vcpuid == XEN_MC_VCPUID_INVALID)
- vmce_vcpuid = VMCE_INJECT_BROADCAST;
- else
- vmce_vcpuid = global->mc_vcpuid;
-
/* We will inject vMCE to DOMU*/
if ( inject_vmce(d, vmce_vcpuid) < 0 )
{
diff --git a/xen/arch/x86/cpu/mcheck/vmce.c b/xen/arch/x86/cpu/mcheck/vmce.c
index 13b692c..2caccae 100644
--- a/xen/arch/x86/cpu/mcheck/vmce.c
+++ b/xen/arch/x86/cpu/mcheck/vmce.c
@@ -381,38 +381,66 @@ int inject_vmce(struct domain *d, int vcpu)
return ret;
}
-int fill_vmsr_data(struct mcinfo_bank *mc_bank, struct domain *d,
- uint64_t gstatus)
+static int vcpu_fill_mc_msrs(struct vcpu *v, uint64_t mcg_status,
+ uint64_t mci_status, uint64_t mci_addr,
+ uint64_t mci_misc)
{
- struct vcpu *v = d->vcpu[0];
-
- if ( mc_bank->mc_domid != DOMID_INVALID )
+ if ( v->arch.vmce.mcg_status & MCG_STATUS_MCIP )
{
- if ( v->arch.vmce.mcg_status & MCG_STATUS_MCIP )
- {
- mce_printk(MCE_QUIET, "MCE: guest has not handled previous"
- " vMCE yet!\n");
- return -1;
- }
+ mce_printk(MCE_QUIET, "MCE: %pv: guest has not handled previous"
+ " vMCE yet!\n", v);
+ return -EBUSY;
+ }
- spin_lock(&v->arch.vmce.lock);
+ spin_lock(&v->arch.vmce.lock);
- v->arch.vmce.mcg_status = gstatus;
- /*
- * 1. Skip bank 0 to avoid 'bank 0 quirk' of old processors
- * 2. Filter MCi_STATUS MSCOD model specific error code to guest
- */
- v->arch.vmce.bank[1].mci_status = mc_bank->mc_status &
- MCi_STATUS_MSCOD_MASK;
- v->arch.vmce.bank[1].mci_addr = mc_bank->mc_addr;
- v->arch.vmce.bank[1].mci_misc = mc_bank->mc_misc;
+ v->arch.vmce.mcg_status = mcg_status;
+ /*
+ * 1. Skip bank 0 to avoid 'bank 0 quirk' of old processors
+ * 2. Filter MCi_STATUS MSCOD model specific error code to guest
+ */
+ v->arch.vmce.bank[1].mci_status = mci_status & MCi_STATUS_MSCOD_MASK;
+ v->arch.vmce.bank[1].mci_addr = mci_addr;
+ v->arch.vmce.bank[1].mci_misc = mci_misc;
- spin_unlock(&v->arch.vmce.lock);
- }
+ spin_unlock(&v->arch.vmce.lock);
return 0;
}
+int fill_vmsr_data(struct mcinfo_bank *mc_bank, struct domain *d,
+ uint64_t gstatus, bool broadcast)
+{
+ struct vcpu *v = d->vcpu[0];
+ int ret, err;
+
+ if ( mc_bank->mc_domid == DOMID_INVALID )
+ return -EINVAL;
+
+ /*
+ * vMCE with the actual error information is injected to vCPU0,
+ * and, if broadcast is required, we choose to inject less severe
+ * vMCEs to other vCPUs. Thus guest can always get the severest
+ * error (i.e. the actual one) on vCPU0. If guest can recover from
+ * the severest error on vCPU0, the less severe errors on other
+ * vCPUs will not prevent guest from recovering on those vCPUs.
+ */
+ ret = vcpu_fill_mc_msrs(v, gstatus, mc_bank->mc_status,
+ mc_bank->mc_addr, mc_bank->mc_misc);
+ if ( broadcast )
+ for_each_vcpu ( d, v )
+ {
+ if ( !v->vcpu_id )
+ continue;
+ err = vcpu_fill_mc_msrs(v, MCG_STATUS_MCIP | MCG_STATUS_RIPV,
+ 0, 0, 0);
+ if ( err )
+ ret = err;
+ }
+
+ return ret;
+}
+
/* It's said some ram is setup as mmio_direct for UC cache attribute */
#define P2M_UNMAP_TYPES (p2m_to_mask(p2m_ram_rw) \
| p2m_to_mask(p2m_ram_logdirty) \
diff --git a/xen/arch/x86/cpu/mcheck/vmce.h b/xen/arch/x86/cpu/mcheck/vmce.h
index 163ce3c..74f6381 100644
--- a/xen/arch/x86/cpu/mcheck/vmce.h
+++ b/xen/arch/x86/cpu/mcheck/vmce.h
@@ -17,7 +17,7 @@ int vmce_amd_rdmsr(const struct vcpu *, uint32_t msr,
uint64_t *val);
int vmce_amd_wrmsr(struct vcpu *, uint32_t msr, uint64_t val);
int fill_vmsr_data(struct mcinfo_bank *mc_bank, struct domain *d,
- uint64_t gstatus);
+ uint64_t gstatus, bool broadcast);
#define VMCE_INJECT_BROADCAST (-1)
int inject_vmce(struct domain *d, int vcpu);
--
2.10.1
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