Re: [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line
From: David Brazdil <hidden>
Date: 2021-01-18 13:18:10
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kvmarm, lkml
On Mon, Jan 18, 2021 at 09:45:26AM +0000, Marc Zyngier wrote:
Finally we can check whether VHE is disabled on the command line, and not enable it if that's the user's wish. Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <redacted>
quoted hunk ↗ jump to hunk
--- arch/arm64/kernel/hyp-stub.S | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 59820f9b8522..bbab2148a2a2 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S@@ -77,13 +77,24 @@ SYM_CODE_END(el1_sync) SYM_CODE_START_LOCAL(mutate_to_vhe) // Sanity check: MMU *must* be off mrs x0, sctlr_el2 - tbnz x0, #0, 1f + tbnz x0, #0, 2f // Needs to be VHE capable, obviously mrs x0, id_aa64mmfr1_el1 ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4 - cbz x0, 1f + cbz x0, 2f + // Check whether VHE is disabled from the command line + adr_l x1, id_aa64mmfr1_val + ldr x0, [x1] + adr_l x1, id_aa64mmfr1_mask + ldr x1, [x1]
super nit: There's a ldr_l macro
quoted hunk ↗ jump to hunk
+ ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4 + ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4 + cbz x1, 1f + and x0, x0, x1 + cbz x0, 2f +1: // Engage the VHE magic! mov_q x0, HCR_HOST_VHE_FLAGS msr hcr_el2, x0@@ -152,7 +163,7 @@ skip_spe: orr x0, x0, x1 msr spsr_el1, x0 -1: eret +2: eret SYM_CODE_END(mutate_to_vhe) .macro invalid_vector label-- 2.29.2
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