[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH RFC 09/12] x86/np2m: improve nestedhvm_hap_nested_page_fault()
There is a possibility for nested_p2m to became stale between nestedhvm_hap_nested_page_fault() and nestedhap_fix_p2m(). Simply use p2m_get_nestedp2m_lock() to guarantee that correct np2m is used. Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx> --- xen/arch/x86/mm/hap/nested_hap.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/xen/arch/x86/mm/hap/nested_hap.c b/xen/arch/x86/mm/hap/nested_hap.c index ed137fa784..96afe632b5 100644 --- a/xen/arch/x86/mm/hap/nested_hap.c +++ b/xen/arch/x86/mm/hap/nested_hap.c @@ -101,28 +101,21 @@ nestedhap_fix_p2m(struct vcpu *v, struct p2m_domain *p2m, unsigned int page_order, p2m_type_t p2mt, p2m_access_t p2ma) { int rc = 0; + unsigned long gfn, mask; + mfn_t mfn; + ASSERT(p2m); ASSERT(p2m->set_entry); + ASSERT(p2m_locked_by_me(p2m)); - p2m_lock(p2m); - - /* If this p2m table has been flushed or recycled under our feet, - * leave it alone. We'll pick up the right one as we try to - * vmenter the guest. */ - if ( p2m->np2m_base == nhvm_vcpu_p2m_base(v) ) - { - unsigned long gfn, mask; - mfn_t mfn; - - /* If this is a superpage mapping, round down both addresses - * to the start of the superpage. */ - mask = ~((1UL << page_order) - 1); + /* If this is a superpage mapping, round down both addresses + * to the start of the superpage. */ + mask = ~((1UL << page_order) - 1); - gfn = (L2_gpa >> PAGE_SHIFT) & mask; - mfn = _mfn((L0_gpa >> PAGE_SHIFT) & mask); + gfn = (L2_gpa >> PAGE_SHIFT) & mask; + mfn = _mfn((L0_gpa >> PAGE_SHIFT) & mask); - rc = p2m_set_entry(p2m, gfn, mfn, page_order, p2mt, p2ma); - } + rc = p2m_set_entry(p2m, gfn, mfn, page_order, p2mt, p2ma); p2m_unlock(p2m); @@ -212,7 +205,6 @@ nestedhvm_hap_nested_page_fault(struct vcpu *v, paddr_t *L2_gpa, uint8_t p2ma_21 = p2m_access_rwx; p2m = p2m_get_hostp2m(d); /* L0 p2m */ - nested_p2m = p2m_get_nestedp2m(v); /* walk the L1 P2M table */ rv = nestedhap_walk_L1_p2m(v, *L2_gpa, &L1_gpa, &page_order_21, &p2ma_21, @@ -278,6 +270,7 @@ nestedhvm_hap_nested_page_fault(struct vcpu *v, paddr_t *L2_gpa, p2ma_10 &= (p2m_access_t)p2ma_21; /* fix p2m_get_pagetable(nested_p2m) */ + nested_p2m = p2m_get_nestedp2m_locked(v); nestedhap_fix_p2m(v, nested_p2m, *L2_gpa, L0_gpa, page_order_20, p2mt_10, p2ma_10); -- 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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