From: Marc Zyngier <maz@kernel.org>
To: David Brazdil <dbrazdil@google.com>
Cc: kvmarm@lists.cs.columbia.edu,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 8/8] KVM: arm64: Remove hyp_symbol_addr
Date: Sat, 23 Jan 2021 13:54:47 +0000 [thread overview]
Message-ID: <87y2gjkbbs.wl-maz@kernel.org> (raw)
In-Reply-To: <20210105180541.65031-9-dbrazdil@google.com>
On Tue, 05 Jan 2021 18:05:41 +0000,
David Brazdil <dbrazdil@google.com> wrote:
>
> Hyp code used the hyp_symbol_addr helper to force PC-relative addressing
> because absolute addressing results in kernel VAs due to the way hyp
> code is linked. This is not true anymore, so remove the helper and
> update all of its users.
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
> Signed-off-by: David Brazdil <dbrazdil@google.com>
> ---
> arch/arm64/include/asm/kvm_asm.h | 26 ------------------------
> arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ++--
> arch/arm64/kvm/hyp/nvhe/hyp-smp.c | 4 ++--
> arch/arm64/kvm/hyp/nvhe/psci-relay.c | 24 +++++++++++-----------
> arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c | 2 +-
> 5 files changed, 17 insertions(+), 43 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 8a33d83ea843..22d933e9b59e 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -199,32 +199,6 @@ extern void __vgic_v3_init_lrs(void);
>
> extern u32 __kvm_get_mdcr_el2(void);
>
> -#if defined(GCC_VERSION) && GCC_VERSION < 50000
> -#define SYM_CONSTRAINT "i"
> -#else
> -#define SYM_CONSTRAINT "S"
> -#endif
> -
> -/*
> - * Obtain the PC-relative address of a kernel symbol
> - * s: symbol
> - *
> - * The goal of this macro is to return a symbol's address based on a
> - * PC-relative computation, as opposed to a loading the VA from a
> - * constant pool or something similar. This works well for HYP, as an
> - * absolute VA is guaranteed to be wrong. Only use this if trying to
> - * obtain the address of a symbol (i.e. not something you obtained by
> - * following a pointer).
> - */
> -#define hyp_symbol_addr(s) \
> - ({ \
> - typeof(s) *addr; \
> - asm("adrp %0, %1\n" \
> - "add %0, %0, :lo12:%1\n" \
> - : "=r" (addr) : SYM_CONSTRAINT (&s)); \
> - addr; \
> - })
> -
This hunk is going to conflict in a fairly benign way with the
removal of the GCC workaround which I think Will queued for 5.12.
I'll work something out...
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2021-01-23 13:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 18:05 [PATCH v2 0/8] arm64: Relocate absolute hyp VAs David Brazdil
2021-01-05 18:05 ` [PATCH v2 1/8] KVM: arm64: Rename .idmap.text in hyp linker script David Brazdil
2021-01-05 18:05 ` [PATCH v2 2/8] KVM: arm64: Set up .hyp.rodata ELF section David Brazdil
2021-01-05 18:05 ` [PATCH v2 3/8] KVM: arm64: Add symbol at the beginning of each hyp section David Brazdil
2021-01-23 13:30 ` Marc Zyngier
2021-01-05 18:05 ` [PATCH v2 4/8] KVM: arm64: Generate hyp relocation data David Brazdil
2021-01-29 21:43 ` Guenter Roeck
2021-01-30 12:16 ` Marc Zyngier
2021-01-30 13:44 ` Marc Zyngier
2021-01-30 16:11 ` Guenter Roeck
2021-01-30 18:10 ` Marc Zyngier
2021-02-01 10:42 ` David Brazdil
2021-02-01 12:06 ` Marc Zyngier
2021-01-05 18:05 ` [PATCH v2 5/8] KVM: arm64: Apply hyp relocations at runtime David Brazdil
2021-01-05 18:05 ` [PATCH v2 6/8] KVM: arm64: Fix constant-pool users in hyp David Brazdil
2021-01-05 18:05 ` [PATCH v2 7/8] KVM: arm64: Remove patching of fn pointers " David Brazdil
2021-01-05 18:05 ` [PATCH v2 8/8] KVM: arm64: Remove hyp_symbol_addr David Brazdil
2021-01-23 13:54 ` Marc Zyngier [this message]
2021-01-23 14:45 ` [PATCH v2 0/8] arm64: Relocate absolute hyp VAs Marc Zyngier
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