66 lines
2.3 KiB
Diff
66 lines
2.3 KiB
Diff
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From: Bruce Rogers <brogers@suse.com>
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Date: Fri, 15 Feb 2019 15:12:04 -0700
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Subject: Revert "target/i386: kvm: add VMX migration blocker"
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This reverts commit d98f26073bebddcd3da0ba1b86c3a34e840c0fb8.
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Here is some text explaining the revert:
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I've thought about this some more, and with upstream
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discussions about it having stagnated, at this point I think
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the best solution is to revert the patch which considers it
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a migration blocker to have the vmx feature enabled. It's
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worth noting that not only are migrations blocked, but
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saving of the vm state via save/restore and snapshots.
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Given that it is still widely known that Nested Virtualization
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is not supported by SUSE and other vendors, but is still used
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by quite a few people who understand that there are caveats
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with it's usage, I believe this migration blocker is more
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hurtful than helpful.
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The fact that as of the v4.20 kernel, nested virtualization is
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enabled by default (for vmx), was partly why the patch was
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added in the first place. But my perspective is that perhaps
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enabling nested was still a bit premature.
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I will make sure our qemu changelog explains that despite
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removing that migration blocker, the user is warned that
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nested virtualization is still a "use at your own risk
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feature".
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[BR: BSC#1121604]
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Signed-off-by: Bruce Rogers <brogers@suse.com>
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---
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target/i386/kvm.c | 12 ------------
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1 file changed, 12 deletions(-)
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diff --git a/target/i386/kvm.c b/target/i386/kvm.c
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index b2401d13ea..f97bfc164d 100644
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--- a/target/i386/kvm.c
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+++ b/target/i386/kvm.c
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@@ -855,7 +855,6 @@ static int hyperv_init_vcpu(X86CPU *cpu)
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}
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static Error *invtsc_mig_blocker;
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-static Error *vmx_mig_blocker;
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#define KVM_MAX_CPUID_ENTRIES 100
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@@ -1248,17 +1247,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
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!!(c->ecx & CPUID_EXT_SMX);
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}
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- if ((env->features[FEAT_1_ECX] & CPUID_EXT_VMX) && !vmx_mig_blocker) {
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- error_setg(&vmx_mig_blocker,
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- "Nested VMX virtualization does not support live migration yet");
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- r = migrate_add_blocker(vmx_mig_blocker, &local_err);
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- if (local_err) {
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- error_report_err(local_err);
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- error_free(vmx_mig_blocker);
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- return r;
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- }
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- }
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-
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if (env->mcg_cap & MCG_LMCE_P) {
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has_msr_mcg_ext_ctl = has_msr_feature_control = true;
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}
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