[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] x86/shadow: drop redundant present bit checks from FOREACH_PRESENT_L<N>E() "bodies"
commit dc7be3979ce52fb30d89ab53b72e9e19891a8d9a Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Fri Mar 31 08:12:45 2023 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Fri Mar 31 08:12:45 2023 +0200 x86/shadow: drop redundant present bit checks from FOREACH_PRESENT_L<N>E() "bodies" FOREACH_PRESENT_L<N>E(), as their names (now) say, already invoke the "body" only when the present bit is set; no need to re-do the check. While there also - stop open-coding mfn_to_maddr() in code being touched (re-indented) anyway, - stop open-coding mfn_eq() in code being touched or in adjacent code, - drop local variables when they're no longer used at least twice. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> --- xen/arch/x86/mm/shadow/multi.c | 54 ++++++++++++------------------------------ 1 file changed, 15 insertions(+), 39 deletions(-) diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c index 8319874b42..ddcf34972d 100644 --- a/xen/arch/x86/mm/shadow/multi.c +++ b/xen/arch/x86/mm/shadow/multi.c @@ -1289,12 +1289,8 @@ void sh_destroy_l4_shadow(struct domain *d, mfn_t smfn) /* Decrement refcounts of all the old entries */ sl4mfn = smfn; FOREACH_PRESENT_L4E(sl4mfn, sl4e, NULL, 0, d, { - if ( shadow_l4e_get_flags(*sl4e) & _PAGE_PRESENT ) - { - sh_put_ref(d, shadow_l4e_get_mfn(*sl4e), - (((paddr_t)mfn_x(sl4mfn)) << PAGE_SHIFT) - | ((unsigned long)sl4e & ~PAGE_MASK)); - } + sh_put_ref(d, shadow_l4e_get_mfn(*sl4e), + mfn_to_maddr(sl4mfn) | ((unsigned long)sl4e & ~PAGE_MASK)); }); /* Put the memory back in the pool */ @@ -1320,10 +1316,8 @@ void sh_destroy_l3_shadow(struct domain *d, mfn_t smfn) /* Decrement refcounts of all the old entries */ sl3mfn = smfn; FOREACH_PRESENT_L3E(sl3mfn, sl3e, NULL, 0, { - if ( shadow_l3e_get_flags(*sl3e) & _PAGE_PRESENT ) - sh_put_ref(d, shadow_l3e_get_mfn(*sl3e), - (((paddr_t)mfn_x(sl3mfn)) << PAGE_SHIFT) - | ((unsigned long)sl3e & ~PAGE_MASK)); + sh_put_ref(d, shadow_l3e_get_mfn(*sl3e), + mfn_to_maddr(sl3mfn) | ((unsigned long)sl3e & ~PAGE_MASK)); }); /* Put the memory back in the pool */ @@ -1352,10 +1346,8 @@ void sh_destroy_l2_shadow(struct domain *d, mfn_t smfn) /* Decrement refcounts of all the old entries */ sl2mfn = smfn; FOREACH_PRESENT_L2E(sl2mfn, sl2e, NULL, 0, d, { - if ( shadow_l2e_get_flags(*sl2e) & _PAGE_PRESENT ) - sh_put_ref(d, shadow_l2e_get_mfn(*sl2e), - (((paddr_t)mfn_x(sl2mfn)) << PAGE_SHIFT) - | ((unsigned long)sl2e & ~PAGE_MASK)); + sh_put_ref(d, shadow_l2e_get_mfn(*sl2e), + mfn_to_maddr(sl2mfn) | ((unsigned long)sl2e & ~PAGE_MASK)); }); /* Put the memory back in the pool */ @@ -1390,11 +1382,10 @@ void sh_destroy_l1_shadow(struct domain *d, mfn_t smfn) /* Decrement refcounts of all the old entries */ mfn_t sl1mfn = smfn; FOREACH_PRESENT_L1E(sl1mfn, sl1e, NULL, 0, { - unsigned int sl1f = shadow_l1e_get_flags(*sl1e); - - if ( (sl1f & _PAGE_PRESENT) && !sh_l1e_is_magic(*sl1e) ) + if ( !sh_l1e_is_magic(*sl1e) ) { - shadow_vram_put_mfn(shadow_l1e_get_mfn(*sl1e), sl1f, + shadow_vram_put_mfn(shadow_l1e_get_mfn(*sl1e), + shadow_l1e_get_flags(*sl1e), sl1mfn, sl1e, d); shadow_put_page_from_l1e(*sl1e, d); } @@ -3558,7 +3549,6 @@ int cf_check sh_rm_write_access_from_l1( { shadow_l1e_t *sl1e; int done = 0; - int flags; #if SHADOW_OPTIMIZATIONS & SHOPT_WRITABLE_HEURISTIC struct vcpu *curr = current; mfn_t base_sl1mfn = sl1mfn; /* Because sl1mfn changes in the foreach */ @@ -3566,10 +3556,8 @@ int cf_check sh_rm_write_access_from_l1( FOREACH_PRESENT_L1E(sl1mfn, sl1e, NULL, done, { - flags = shadow_l1e_get_flags(*sl1e); - if ( (flags & _PAGE_PRESENT) - && (flags & _PAGE_RW) - && (mfn_x(shadow_l1e_get_mfn(*sl1e)) == mfn_x(readonly_mfn)) ) + if ( (shadow_l1e_get_flags(*sl1e) & _PAGE_RW) && + mfn_eq(shadow_l1e_get_mfn(*sl1e), readonly_mfn) ) { shadow_l1e_t ro_sl1e = shadow_l1e_remove_flags(*sl1e, _PAGE_RW); @@ -3595,13 +3583,10 @@ int cf_check sh_rm_mappings_from_l1( { shadow_l1e_t *sl1e; int done = 0; - int flags; FOREACH_PRESENT_L1E(sl1mfn, sl1e, NULL, done, { - flags = shadow_l1e_get_flags(*sl1e); - if ( (flags & _PAGE_PRESENT) - && (mfn_x(shadow_l1e_get_mfn(*sl1e)) == mfn_x(target_mfn)) ) + if ( mfn_eq(shadow_l1e_get_mfn(*sl1e), target_mfn) ) { shadow_set_l1e(d, sl1e, shadow_l1e_empty(), p2m_invalid, sl1mfn); if ( sh_check_page_has_no_refs(mfn_to_page(target_mfn)) ) @@ -3646,13 +3631,10 @@ int cf_check sh_remove_l1_shadow(struct domain *d, mfn_t sl2mfn, mfn_t sl1mfn) { shadow_l2e_t *sl2e; int done = 0; - int flags; FOREACH_PRESENT_L2E(sl2mfn, sl2e, NULL, done, d, { - flags = shadow_l2e_get_flags(*sl2e); - if ( (flags & _PAGE_PRESENT) - && (mfn_x(shadow_l2e_get_mfn(*sl2e)) == mfn_x(sl1mfn)) ) + if ( mfn_eq(shadow_l2e_get_mfn(*sl2e), sl1mfn) ) { shadow_set_l2e(d, sl2e, shadow_l2e_empty(), sl2mfn); if ( mfn_to_page(sl1mfn)->u.sh.type == 0 ) @@ -3669,13 +3651,10 @@ int cf_check sh_remove_l2_shadow(struct domain *d, mfn_t sl3mfn, mfn_t sl2mfn) { shadow_l3e_t *sl3e; int done = 0; - int flags; FOREACH_PRESENT_L3E(sl3mfn, sl3e, NULL, done, { - flags = shadow_l3e_get_flags(*sl3e); - if ( (flags & _PAGE_PRESENT) - && (mfn_x(shadow_l3e_get_mfn(*sl3e)) == mfn_x(sl2mfn)) ) + if ( mfn_eq(shadow_l3e_get_mfn(*sl3e), sl2mfn) ) { shadow_set_l3e(d, sl3e, shadow_l3e_empty(), sl3mfn); if ( mfn_to_page(sl2mfn)->u.sh.type == 0 ) @@ -3691,13 +3670,10 @@ int cf_check sh_remove_l3_shadow(struct domain *d, mfn_t sl4mfn, mfn_t sl3mfn) { shadow_l4e_t *sl4e; int done = 0; - int flags; FOREACH_PRESENT_L4E(sl4mfn, sl4e, NULL, done, d, { - flags = shadow_l4e_get_flags(*sl4e); - if ( (flags & _PAGE_PRESENT) - && (mfn_x(shadow_l4e_get_mfn(*sl4e)) == mfn_x(sl3mfn)) ) + if ( mfn_eq(shadow_l4e_get_mfn(*sl4e), sl3mfn) ) { shadow_set_l4e(d, sl4e, shadow_l4e_empty(), sl4mfn); if ( mfn_to_page(sl3mfn)->u.sh.type == 0 ) -- generated by git-patchbot for /home/xen/git/xen.git#master
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