From: Julien Grall <julien.grall@arm.com>
To: xen-devel@lists.xen.org
Cc: andre.przywara@arm.com, Julien Grall <julien.grall@arm.com>,
sstabellini@kernel.org, tamas@tklengyel.com
Subject: [for-4.7 2/2] xen/arm: traps: Correctly interpret the content of the register HPFAR_EL2
Date: Wed, 13 Apr 2016 16:55:31 +0100 [thread overview]
Message-ID: <1460562931-19858-3-git-send-email-julien.grall@arm.com> (raw)
In-Reply-To: <1460562931-19858-1-git-send-email-julien.grall@arm.com>
The register HPFAR_EL2 (resp. HPFAR on arm32) contains the bits [47:12]
(resp. [39:12]) of the faulting IPA. Unlike other registers that represent
an address, the upper bits of the IPA are stored in the register bits
[4:39] (resp. [4:21]).
However, Xen assumes that the register contains the faulting IPA correctly
offsetted. This will result to get a wrong IPA when the fault is happening
during a translation table walk. Note this is only affecting memaccess.
Introduce a new helper to get the faulting IPA from HPFAR_EL2 and
replace direct read from the register by the helper.
Signed-off-by: Julien Grall <julien.grall@arm.com>
---
Cc: tamas@tklengyel.com
This is a bug fix for Xen 4.7 and should also be backported to Xen 4.6.
Without this patch, the faulting IPA reported to memaccess may be wrong.
---
xen/arch/arm/traps.c | 11 +++++++++--
xen/include/asm-arm/processor.h | 7 +++++++
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 1516abd..5e865cf 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2363,6 +2363,13 @@ done:
if (first) unmap_domain_page(first);
}
+static inline paddr_t get_faulting_ipa(void)
+{
+ register_t hpfar = READ_SYSREG(HPFAR_EL2);
+
+ return ((paddr_t)(hpfar & HPFAR_MASK) << (12 - 4));
+}
+
static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
const union hsr hsr)
{
@@ -2381,7 +2388,7 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
};
if ( hsr.iabt.s1ptw )
- gpa = READ_SYSREG(HPFAR_EL2);
+ gpa = get_faulting_ipa();
else
{
/*
@@ -2431,7 +2438,7 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs,
#endif
if ( dabt.s1ptw )
- info.gpa = READ_SYSREG(HPFAR_EL2);
+ info.gpa = get_faulting_ipa();
else
{
rc = gva_to_ipa(info.gva, &info.gpa, GV2M_READ);
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 7e6eb66..6789cd0 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -565,6 +565,13 @@ union hsr {
#define FSC_LL_MASK (_AC(0x03,U)<<0)
+/* HPFAR_EL2: Hypervisor IPA Fault Address Register */
+#ifdef CONFIG_ARM_64
+#define HPFAR_MASK GENMASK(39, 4)
+#else
+#define HPFAR_MASK GENMASK(31, 4)
+#endif
+
/* Time counter hypervisor control register */
#define CNTHCTL_EL2_EL1PCTEN (1u<<0) /* Kernel/user access to physical counter */
#define CNTHCTL_EL2_EL1PCEN (1u<<1) /* Kernel/user access to CNTP timer regs */
--
1.9.1
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next prev parent reply other threads:[~2016-04-13 15:55 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-13 15:55 [for-4.7 0/2] xen/arm: traps: Correctly interpret the content of the register HPFAR_EL2 Julien Grall
2016-04-13 15:55 ` [for-4.7 1/2] xen/bitops: Introduce macros to generate mask Julien Grall
2016-04-13 18:07 ` Stefano Stabellini
2016-04-13 18:14 ` Andrew Cooper
2016-04-14 8:47 ` Julien Grall
2016-04-14 4:01 ` Jan Beulich
2016-04-14 8:55 ` Julien Grall
2016-04-14 14:56 ` Jan Beulich
2016-04-14 15:08 ` Julien Grall
2016-04-14 15:23 ` Jan Beulich
2016-04-20 12:35 ` Julien Grall
2016-04-20 16:43 ` Jan Beulich
2016-04-22 11:33 ` Julien Grall
2016-04-22 11:49 ` Stefano Stabellini
2016-04-22 15:33 ` Julien Grall
2016-04-22 15:42 ` Stefano Stabellini
2016-04-13 15:55 ` Julien Grall [this message]
2016-04-13 18:17 ` [for-4.7 2/2] xen/arm: traps: Correctly interpret the content of the register HPFAR_EL2 Stefano Stabellini
2016-04-13 19:11 ` Tamas K Lengyel
2016-04-13 20:33 ` André Przywara
2016-04-14 17:47 ` [for-4.7 0/2] " Wei Liu
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