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authorAlex Bennée <alex.bennee@linaro.org>2022-04-26 16:55:29 +0100
committerAlex Bennée <alex.bennee@linaro.org>2022-04-26 17:04:06 +0100
commit7eb8b98dd3e8aaba06202aac8797e2eb5fbd04b8 (patch)
tree4a268566c5d03622a85799d260204810430b7ef1 /xen/arch/arm/p2m.c
parent0941d6cb2383c4e87d7f53f1df74e8850e1649bc (diff)
xen/arm: p2m don't fall over on FEAT_LPA enabled hwfix/arm-feat-lpa
When we introduced FEAT_LPA to QEMU's -cpu max we discovered older kernels had a bug where the physical address was copied directly from ID_AA64MMFR0_EL1.PARange field. The early cpu_init code of Xen commits the same error by blindly copying across the max supported range. Unsurprisingly when the page tables aren't set up for these greater ranges hilarity ensues and the hypervisor crashes fairly early on in the boot-up sequence. This happens when we write to the control register in enable_mmu(). Attempt to fix this the same way as the Linux kernel does by gating PARange to the maximum the hypervisor can handle. I also had to fix up code in p2m which panics when it sees an "invalid" entry in PARange. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Julien Grall <julien@xen.org> Cc: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com> Cc: Bertrand Marquis <bertrand.marquis@arm.com>
Diffstat (limited to 'xen/arch/arm/p2m.c')
-rw-r--r--xen/arch/arm/p2m.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index fb71fa4c1c..e5a88095f8 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -2030,7 +2030,7 @@ void __init setup_virt_paging(void)
unsigned int root_order; /* Page order of the root of the p2m */
unsigned int sl0; /* Desired SL0, maximum in comment */
} pa_range_info[] = {
- /* T0SZ minimum and SL0 maximum from ARM DDI 0487A.b Table D4-5 */
+ /* T0SZ minimum and SL0 maximum from ARM DDI 0487H.a Table D5-6 */
/* PA size, t0sz(min), root-order, sl0(max) */
[0] = { 32, 32/*32*/, 0, 1 },
[1] = { 36, 28/*28*/, 0, 1 },
@@ -2038,7 +2038,7 @@ void __init setup_virt_paging(void)
[3] = { 42, 22/*22*/, 3, 1 },
[4] = { 44, 20/*20*/, 0, 2 },
[5] = { 48, 16/*16*/, 0, 2 },
- [6] = { 0 }, /* Invalid */
+ [6] = { 52, 12/*12*/, 3, 3 },
[7] = { 0 } /* Invalid */
};
@@ -2069,10 +2069,13 @@ void __init setup_virt_paging(void)
}
}
- /* pa_range is 4 bits, but the defined encodings are only 3 bits */
+ /* pa_range is 4 bits but we don't support all modes */
if ( pa_range >= ARRAY_SIZE(pa_range_info) || !pa_range_info[pa_range].pabits )
panic("Unknown encoding of ID_AA64MMFR0_EL1.PARange %x\n", pa_range);
+ if ( pa_range > 5 )
+ pa_range = 5;
+
val |= VTCR_PS(pa_range);
val |= VTCR_TG0_4K;