lkml.org 
[lkml]   [2020]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 5/9] KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes
Date
Set kvm_x86_ops with the vendor's ops only after ->hardware_setup()
completes to "prevent" using kvm_x86_ops before they are ready, i.e. to
generate a null pointer fault instead of silently consuming unconfigured
state.

An alternative implementation would be to have ->hardware_setup()
return the vendor's ops, but that would require non-trivial refactoring,
and would arguably result in less readable code, e.g. ->hardware_setup()
would need to use ERR_PTR() in multiple locations, and each vendor's
declaration of the runtime ops would be less obvious.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/x86.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 20f989d1bba8..eb1976214ada 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7354,8 +7354,6 @@ int kvm_arch_init(void *opaque)
if (r)
goto out_free_percpu;

- kvm_x86_ops = ops->runtime_ops;
-
kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK,
PT_DIRTY_MASK, PT64_NX_MASK, 0,
PT_PRESENT_MASK, 0, sme_me_mask);
@@ -9635,6 +9633,8 @@ int kvm_arch_hardware_setup(void *opaque)
if (r != 0)
return r;

+ kvm_x86_ops = ops->runtime_ops;
+
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
supported_xss = 0;

--
2.24.1
\
 
 \ /
  Last update: 2020-03-21 21:27    [W:0.172 / U:4.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site