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| author | Ingo Molnar <mingo@elte.hu> | 2007-03-11 13:52:33 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2007-03-27 17:55:48 +0200 |
| commit | 6d9658df07789a124e5c1f8677afcd7773439f3e (patch) | |
| tree | ad7b6c562c1d52f9794508c0e29ff18e73bc795e /drivers/kvm | |
| parent | 6af11b9e827aac1d664ccd31e94f122c7698416b (diff) | |
| download | linux-3.10-6d9658df07789a124e5c1f8677afcd7773439f3e.tar.gz linux-3.10-6d9658df07789a124e5c1f8677afcd7773439f3e.tar.bz2 linux-3.10-6d9658df07789a124e5c1f8677afcd7773439f3e.zip | |
KVM: always reload segment selectors
failed VM entry on VMX might still change %fs or %gs, thus make sure
that KVM always reloads the segment selectors. This is crutial on both
x86 and x86_64: x86 has __KERNEL_PDA in %fs on which things like
'current' depends and x86_64 has 0 there and needs MSR_GS_BASE to work.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/vmx.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 25b24719922..fbbf9d6b299 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1888,6 +1888,27 @@ again: [cr2]"i"(offsetof(struct kvm_vcpu, cr2)) : "cc", "memory" ); + /* + * Reload segment selectors ASAP. (it's needed for a functional + * kernel: x86 relies on having __KERNEL_PDA in %fs and x86_64 + * relies on having 0 in %gs for the CPU PDA to work.) + */ + if (fs_gs_ldt_reload_needed) { + load_ldt(ldt_sel); + load_fs(fs_sel); + /* + * If we have to reload gs, we must take care to + * preserve our gs base. + */ + local_irq_disable(); + load_gs(gs_sel); +#ifdef CONFIG_X86_64 + wrmsrl(MSR_GS_BASE, vmcs_readl(HOST_GS_BASE)); +#endif + local_irq_enable(); + + reload_tss(); + } ++kvm_stat.exits; save_msrs(vcpu->guest_msrs, NR_BAD_MSRS); @@ -1905,22 +1926,6 @@ again: kvm_run->exit_reason = vmcs_read32(VM_INSTRUCTION_ERROR); r = 0; } else { - if (fs_gs_ldt_reload_needed) { - load_ldt(ldt_sel); - load_fs(fs_sel); - /* - * If we have to reload gs, we must take care to - * preserve our gs base. - */ - local_irq_disable(); - load_gs(gs_sel); -#ifdef CONFIG_X86_64 - wrmsrl(MSR_GS_BASE, vmcs_readl(HOST_GS_BASE)); -#endif - local_irq_enable(); - - reload_tss(); - } /* * Profile KVM exit RIPs: */ |