lkml.org 
[lkml]   [2021]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized
Date
Right now, svm_hv_vmcb_dirty_nested_enlightenments has an incorrect
dereference of vmcb->control.reserved_sw before the vmcb is checked
for being non-NULL. The compiler is usually sinking the dereference
after the check; instead of doing this ourselves in the source,
ensure that svm_hv_vmcb_dirty_nested_enlightenments is only called
with a non-NULL VMCB.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Vineeth Pillai <viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Untested for now due to issues with my AMD machine. - Paolo]
---
arch/x86/kvm/svm/svm.c | 4 ++--
arch/x86/kvm/svm/svm_onhyperv.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9a6987549e1b..4bcb95bb8ed7 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1406,8 +1406,6 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
goto error_free_vmsa_page;
}

- svm_vcpu_init_msrpm(vcpu, svm->msrpm);
-
svm->vmcb01.ptr = page_address(vmcb01_page);
svm->vmcb01.pa = __sme_set(page_to_pfn(vmcb01_page) << PAGE_SHIFT);

@@ -1419,6 +1417,8 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu)
svm_switch_vmcb(svm, &svm->vmcb01);
init_vmcb(vcpu);

+ svm_vcpu_init_msrpm(vcpu, svm->msrpm);
+
svm_init_osvw(vcpu);
vcpu->arch.microcode_version = 0x01000065;

diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index 9b9a55abc29f..c53b8bf8d013 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -89,7 +89,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
* as we mark it dirty unconditionally towards end of vcpu
* init phase.
*/
- if (vmcb && vmcb_is_clean(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS) &&
+ if (vmcb_is_clean(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS) &&
hve->hv_enlightenments_control.msr_bitmap)
vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
}
--
2.27.0
\
 
 \ /
  Last update: 2021-07-26 19:02    [W:1.114 / U:0.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site