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Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , Paolo Bonzini , Alexandre Chartre , Liran Alon , Jan Setje-Eilers , Catalin Marinas , Will Deacon , Mark Rutland , Andrew Morton , Mel Gorman , Lorenzo Stoakes , David Hildenbrand , Vlastimil Babka , Michal Hocko , Khalid Aziz , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Valentin Schneider , Paul Turner , Reiji Watanabe , Junaid Shahid , Ofir Weisse , Yosry Ahmed , Patrick Bellasi , KP Singh , Alexandra Sandulescu , Matteo Rizzo , Jann Horn Cc: x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, Brendan Jackman Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Junaid Shahid When ASI is active, __get_current_cr3_fast() adjusts the returned CR3 value accordingly to reflect the actual ASI CR3. Signed-off-by: Junaid Shahid Signed-off-by: Brendan Jackman --- arch/x86/mm/tlb.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 34d61b56d33f..02f73a71d4ea 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -18,6 +18,7 @@ #include #include #include +#include #include =20 #include "mm_internal.h" @@ -1125,14 +1126,32 @@ void flush_tlb_kernel_range(unsigned long start, un= signed long end) */ inline_or_noinstr unsigned long __get_current_cr3_fast(void) { - unsigned long cr3 =3D - build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd, - this_cpu_read(cpu_tlbstate.loaded_mm_asid), - tlbstate_lam_cr3_mask()); + unsigned long cr3; + pgd_t *pgd; + u16 asid =3D this_cpu_read(cpu_tlbstate.loaded_mm_asid); + struct asi *asi =3D asi_get_current(); + u16 pcid; + + if (asi) { + pgd =3D asi_pgd(asi); + pcid =3D asi_pcid(asi, asid); + } else { + pgd =3D this_cpu_read(cpu_tlbstate.loaded_mm)->pgd; + pcid =3D kern_pcid(asid); + } + + cr3 =3D build_cr3_pcid(pgd, pcid, tlbstate_lam_cr3_mask(), false); =20 /* For now, be very restrictive about when this can be called. */ VM_WARN_ON(in_nmi() || preemptible()); =20 + /* + * Outside of the ASI critical section, an ASI-restricted CR3 is + * unstable because an interrupt (including an inner interrupt, if we're + * already in one) could cause a persistent asi_exit. + */ + VM_WARN_ON_ONCE(asi && (asi_is_relaxed() || asi_intr_nest_depth())); + VM_BUG_ON(cr3 !=3D __read_cr3()); return cr3; } --=20 2.45.2.993.g49e7a77208-goog