Re: [PATCH v5 05/19] arm64: Detect if in a realm and set RIPAS RAM

[Shanker Donthineni]

Hi Steven,

On 8/19/24 09:10, Steven Price wrote:
> External email: Use caution opening links or attachments
>
>
> On 19/08/2024 15:04, Suzuki K Poulose wrote:
> > Hi Steven
> >
> > On 19/08/2024 14:19, Steven Price wrote:
> > > From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > >
> > > Detect that the VM is a realm guest by the presence of the RSI
> > > interface.
> > >
> > > If in a realm then all memory needs to be marked as RIPAS RAM initially,
> > > the loader may or may not have done this for us. To be sure iterate over
> > > all RAM and mark it as such. Any failure is fatal as that implies the
> > > RAM regions passed to Linux are incorrect - which would mean failing
> > > later when attempting to access non-existent RAM.
> > >
> > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > > Co-developed-by: Steven Price <steven.price@xxxxxxx>
> > > Signed-off-by: Steven Price <steven.price@xxxxxxx>
> > > ---
> > > Changes since v4:
> > >    * Minor tidy ups.
> > > Changes since v3:
> > >    * Provide safe/unsafe versions for converting memory to protected,
> > >      using the safer version only for the early boot.
> > >    * Use the new psci_early_test_conduit() function to avoid calling an
> > >      SMC if EL3 is not present (or not configured to handle an SMC).
> > > Changes since v2:
> > >    * Use DECLARE_STATIC_KEY_FALSE rather than "extern struct
> > >      static_key_false".
> > >    * Rename set_memory_range() to rsi_set_memory_range().
> > >    * Downgrade some BUG()s to WARN()s and handle the condition by
> > >      propagating up the stack. Comment the remaining case that ends in a
> > >      BUG() to explain why.
> > >    * Rely on the return from rsi_request_version() rather than checking
> > >      the version the RMM claims to support.
> > >    * Rename the generic sounding arm64_setup_memory() to
> > >      arm64_rsi_setup_memory() and move the call site to setup_arch().
> > > ---
> > >    arch/arm64/include/asm/rsi.h | 65 ++++++++++++++++++++++++++++++
> > >    arch/arm64/kernel/Makefile   |  3 +-
> > >    arch/arm64/kernel/rsi.c      | 78 ++++++++++++++++++++++++++++++++++++
> > >    arch/arm64/kernel/setup.c    |  8 ++++
> > >    4 files changed, 153 insertions(+), 1 deletion(-)
> > >    create mode 100644 arch/arm64/include/asm/rsi.h
> > >    create mode 100644 arch/arm64/kernel/rsi.c
> > >
> > > diff --git a/arch/arm64/include/asm/rsi.h b/arch/arm64/include/asm/rsi.h
> > > new file mode 100644
> > > index 000000000000..2bc013badbc3
> > > --- /dev/null
> > > +++ b/arch/arm64/include/asm/rsi.h
> > > @@ -0,0 +1,65 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +/*
> > > + * Copyright (C) 2024 ARM Ltd.
> > > + */
> > > +
> > > +#ifndef __ASM_RSI_H_
> > > +#define __ASM_RSI_H_
> > > +
> > > +#include <linux/jump_label.h>
> > > +#include <asm/rsi_cmds.h>

The error number macros are used in this file, but the header file
'<linux/errno.h>' is not included.


> > > +
> > > +DECLARE_STATIC_KEY_FALSE(rsi_present);
> > > +
> > > +void __init arm64_rsi_init(void);
> > > +void __init arm64_rsi_setup_memory(void);
> > > +static inline bool is_realm_world(void)
> > > +{
> > > +    return static_branch_unlikely(&rsi_present);
> > > +}
> > > +
> > > +static inline int rsi_set_memory_range(phys_addr_t start, phys_addr_t
> > > end,
> > > +                       enum ripas state, unsigned long flags)
> > > +{
> > > +    unsigned long ret;
> > > +    phys_addr_t top;
> > > +
> > > +    while (start != end) {
> > > +        ret = rsi_set_addr_range_state(start, end, state, flags, &top);
> > > +        if (WARN_ON(ret || top < start || top > end))
> > > +            return -EINVAL;
> > > +        start = top;
> > > +    }
> > > +
> > > +    return 0;

-Shanker