arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 131 insertions, 0 deletions

diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
new file mode 100644
index 000000000..635c41cc3
--- /dev/null
+++ b/include/asm-generic/hugetlb.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_HUGETLB_H
+#define _ASM_GENERIC_HUGETLB_H
+
+#include <linux/swap.h>
+#include <linux/swapops.h>
+
+static inline unsigned long huge_pte_write(pte_t pte)
+{
+	return pte_write(pte);
+}
+
+static inline unsigned long huge_pte_dirty(pte_t pte)
+{
+	return pte_dirty(pte);
+}
+
+static inline pte_t huge_pte_mkwrite(pte_t pte)
+{
+	return pte_mkwrite_novma(pte);
+}
+
+#ifndef __HAVE_ARCH_HUGE_PTE_WRPROTECT
+static inline pte_t huge_pte_wrprotect(pte_t pte)
+{
+	return pte_wrprotect(pte);
+}
+#endif
+
+static inline pte_t huge_pte_mkdirty(pte_t pte)
+{
+	return pte_mkdirty(pte);
+}
+
+static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
+{
+	return pte_modify(pte, newprot);
+}
+
+#ifndef __HAVE_ARCH_HUGE_PTE_MKUFFD
+static inline pte_t huge_pte_mkuffd(pte_t pte)
+{
+	return huge_pte_wrprotect(pte_mkuffd(pte));
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTE_CLEAR_UFFD
+static inline pte_t huge_pte_clear_uffd(pte_t pte)
+{
+	return pte_clear_uffd(pte);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTE_UFFD
+static inline int huge_pte_uffd(pte_t pte)
+{
+	return pte_uffd(pte);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTE_CLEAR
+static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+		    pte_t *ptep, unsigned long sz)
+{
+	pte_clear(mm, addr, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
+static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+		pte_t *ptep, pte_t pte, unsigned long sz)
+{
+	set_pte_at(mm, addr, ptep, pte);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+		unsigned long addr, pte_t *ptep, unsigned long sz)
+{
+	return ptep_get_and_clear(mm, addr, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
+static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep)
+{
+	return ptep_clear_flush(vma, addr, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTE_NONE
+static inline int huge_pte_none(pte_t pte)
+{
+	return pte_none(pte);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
+static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
+		unsigned long addr, pte_t *ptep)
+{
+	ptep_set_wrprotect(mm, addr, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
+static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+		unsigned long addr, pte_t *ptep,
+		pte_t pte, int dirty)
+{
+	return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+}
+#endif
+
+#ifndef __HAVE_ARCH_HUGE_PTEP_GET
+static inline pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	return ptep_get(ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED
+static inline bool gigantic_page_runtime_supported(void)
+{
+	return IS_ENABLED(CONFIG_ARCH_HAS_GIGANTIC_PAGE);
+}
+#endif /* __HAVE_ARCH_GIGANTIC_PAGE_RUNTIME_SUPPORTED */
+
+#endif /* _ASM_GENERIC_HUGETLB_H */