From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 27 Jul 2017 15:54:46 +0200
Subject: KVM: nVMX: do not pin the VMCS12
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Patch-mainline: v4.13-rc4
Git-commit: 9f744c59746078280ef28163aa136ef3f625804e
References: bsc#1077761
Since the current implementation of VMCS12 does a memcpy in and out
of guest memory, we do not need current_vmcs12 and current_vmcs12_page
anymore. current_vmptr is enough to read and write the VMCS12.
And David Matlack noted:
This patch also fixes dirty tracking (memslot->dirty_bitmap) of the
VMCS12 page by using kvm_write_guest. nested_release_page() only marks
the struct page dirty.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Added David Matlack's note and nested_release_page_clean() fix.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
arch/x86/kvm/vmx.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -414,9 +414,6 @@
/* The guest-physical address of the current VMCS L1 keeps for L2 */
gpa_t current_vmptr;
- /* The host-usable pointer to the above */
- struct page *current_vmcs12_page;
- struct vmcs12 *current_vmcs12;
/*
* Cache of the guest's VMCS, existing outside of guest memory.
* Loaded from guest memory during VMPTRLD. Flushed to guest
@@ -7165,10 +7162,6 @@
if (vmx->nested.current_vmptr == -1ull)
return;
- /* current_vmptr and current_vmcs12 are always set/reset together */
- if (WARN_ON(vmx->nested.current_vmcs12 == NULL))
- return;
-
if (enable_shadow_vmcs) {
/* copy to memory all shadowed fields in case
they were modified */
@@ -7181,13 +7174,11 @@
vmx->nested.posted_intr_nv = -1;
/* Flush VMCS12 to guest memory */
- memcpy(vmx->nested.current_vmcs12, vmx->nested.cached_vmcs12,
- VMCS12_SIZE);
+ kvm_vcpu_write_guest_page(&vmx->vcpu,
+ vmx->nested.current_vmptr >> PAGE_SHIFT,
+ vmx->nested.cached_vmcs12, 0, VMCS12_SIZE);
- kunmap(vmx->nested.current_vmcs12_page);
- nested_release_page(vmx->nested.current_vmcs12_page);
vmx->nested.current_vmptr = -1ull;
- vmx->nested.current_vmcs12 = NULL;
}
/*
@@ -7605,14 +7596,14 @@
}
nested_release_vmcs12(vmx);
- vmx->nested.current_vmcs12 = new_vmcs12;
- vmx->nested.current_vmcs12_page = page;
/*
* Load VMCS12 from guest memory since it is not already
* cached.
*/
- memcpy(vmx->nested.cached_vmcs12,
- vmx->nested.current_vmcs12, VMCS12_SIZE);
+ memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE);
+ kunmap(page);
+ nested_release_page_clean(page);
+
set_current_vmptr(vmx, vmptr);
}
@@ -9259,7 +9250,6 @@
vmx->nested.posted_intr_nv = -1;
vmx->nested.current_vmptr = -1ull;
- vmx->nested.current_vmcs12 = NULL;
vmx->msr_ia32_feature_control_valid_bits = FEATURE_CONTROL_LOCKED;