| Message ID | 1466601669-25398-3-git-send-email-julien.grall@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, 22 Jun 2016, Julien Grall wrote: > Commit c051618 "xen/arm: traps: Correctly interpret the content of the > register HPFAR_EL2" attempted to fix the interpretation of HPFAR_EL2. > > However, the register contains a 4KB-aligned address. This means that > the reported address is not directly usable to know the faulting IPA. > The offset in the 4KB page can be found by looking at the associated virtual > address (FAR_EL2/HDFAR). > > Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > > Cc: Tamas K Lengyel <tamas@tklengyel.com> > > I overlooked the usage of HPFAR_EL2. This is currently only affecting > memaccess. Rather that return that exact address, the address will > always be the base addres of the 4KB page. > > This would need to be backported up to Xen 4.6. > --- > xen/arch/arm/traps.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c > index 0709deb..742f7d3 100644 > --- a/xen/arch/arm/traps.c > +++ b/xen/arch/arm/traps.c > @@ -2371,11 +2371,15 @@ done: > if (first) unmap_domain_page(first); > } > > -static inline paddr_t get_faulting_ipa(void) > +static inline paddr_t get_faulting_ipa(vaddr_t gva) > { > register_t hpfar = READ_SYSREG(HPFAR_EL2); > + paddr_t ipa; > > - return ((paddr_t)(hpfar & HPFAR_MASK) << (12 - 4)); > + ipa = (paddr_t)(hpfar & HPFAR_MASK) << (12 - 4); > + ipa |= gva & ~PAGE_MASK; > + > + return ipa; > } > > static void do_trap_instr_abort_guest(struct cpu_user_regs *regs, > @@ -2396,7 +2400,7 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs, > }; > > if ( hsr.iabt.s1ptw ) > - gpa = get_faulting_ipa(); > + gpa = get_faulting_ipa(gva); > else > { > /* > @@ -2445,7 +2449,7 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs, > #endif > > if ( dabt.s1ptw ) > - info.gpa = get_faulting_ipa(); > + info.gpa = get_faulting_ipa(info.gva); > else > { > rc = gva_to_ipa(info.gva, &info.gpa, GV2M_READ); > -- > 1.9.1 >
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c index 0709deb..742f7d3 100644 --- a/xen/arch/arm/traps.c +++ b/xen/arch/arm/traps.c @@ -2371,11 +2371,15 @@ done: if (first) unmap_domain_page(first); } -static inline paddr_t get_faulting_ipa(void) +static inline paddr_t get_faulting_ipa(vaddr_t gva) { register_t hpfar = READ_SYSREG(HPFAR_EL2); + paddr_t ipa; - return ((paddr_t)(hpfar & HPFAR_MASK) << (12 - 4)); + ipa = (paddr_t)(hpfar & HPFAR_MASK) << (12 - 4); + ipa |= gva & ~PAGE_MASK; + + return ipa; } static void do_trap_instr_abort_guest(struct cpu_user_regs *regs, @@ -2396,7 +2400,7 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs, }; if ( hsr.iabt.s1ptw ) - gpa = get_faulting_ipa(); + gpa = get_faulting_ipa(gva); else { /* @@ -2445,7 +2449,7 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs, #endif if ( dabt.s1ptw ) - info.gpa = get_faulting_ipa(); + info.gpa = get_faulting_ipa(info.gva); else { rc = gva_to_ipa(info.gva, &info.gpa, GV2M_READ);
Commit c051618 "xen/arm: traps: Correctly interpret the content of the register HPFAR_EL2" attempted to fix the interpretation of HPFAR_EL2. However, the register contains a 4KB-aligned address. This means that the reported address is not directly usable to know the faulting IPA. The offset in the 4KB page can be found by looking at the associated virtual address (FAR_EL2/HDFAR). Signed-off-by: Julien Grall <julien.grall@arm.com> --- Cc: Tamas K Lengyel <tamas@tklengyel.com> I overlooked the usage of HPFAR_EL2. This is currently only affecting memaccess. Rather that return that exact address, the address will always be the base addres of the 4KB page. This would need to be backported up to Xen 4.6. --- xen/arch/arm/traps.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)