On Wed, 25 May 2022 12:23:43 +0100
Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
Hi,
> From: Julien Grall <julien.grall@xxxxxxx>
>
> RAM initialization is unnecessarily split between kvm__init_ram() and
> kvm__arch_init(). Move all code related to RAM initialization to
> kvm__init_ram(), making the code easier to follow and to modify.
>
> One thing to note is that the initialization order is slightly altered:
> kvm__arch_enable_mte() and gic__create() are now called before mmap'ing the
> guest RAM. That is perfectly fine, as they don't use the host's mapping of
> the guest memory.
>
> Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
I can confirm that this is just a code move, also MTE and GIC init do not
seem to rely on RAM in any way.
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Cheers,
Andre
> ---
> arm/kvm.c | 52 ++++++++++++++++++++++++++--------------------------
> 1 file changed, 26 insertions(+), 26 deletions(-)
>
> diff --git a/arm/kvm.c b/arm/kvm.c
> index bd44aa350796..abcccfabf59e 100644
> --- a/arm/kvm.c
> +++ b/arm/kvm.c
> @@ -26,9 +26,34 @@ bool kvm__arch_cpu_supports_vm(void)
>
> void kvm__init_ram(struct kvm *kvm)
> {
> - int err;
> u64 phys_start, phys_size;
> void *host_mem;
> + int err;
> +
> + /*
> + * Allocate guest memory. We must align our buffer to 64K to
> + * correlate with the maximum guest page size for virtio-mmio.
> + * If using THP, then our minimal alignment becomes 2M.
> + * 2M trumps 64K, so let's go with that.
> + */
> + kvm->ram_size = kvm->cfg.ram_size;
> + kvm->arch.ram_alloc_size = kvm->ram_size + SZ_2M;
> + kvm->arch.ram_alloc_start = mmap_anon_or_hugetlbfs(kvm,
> + kvm->cfg.hugetlbfs_path,
> + kvm->arch.ram_alloc_size);
> +
> + if (kvm->arch.ram_alloc_start == MAP_FAILED)
> + die("Failed to map %lld bytes for guest memory (%d)",
> + kvm->arch.ram_alloc_size, errno);
> +
> + kvm->ram_start = (void *)ALIGN((unsigned long)kvm->arch.ram_alloc_start,
> + SZ_2M);
> +
> + madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
> + MADV_MERGEABLE);
> +
> + madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
> + MADV_HUGEPAGE);
>
> phys_start = ARM_MEMORY_AREA;
> phys_size = kvm->ram_size;
> @@ -59,31 +84,6 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
>
> void kvm__arch_init(struct kvm *kvm)
> {
> - /*
> - * Allocate guest memory. We must align our buffer to 64K to
> - * correlate with the maximum guest page size for virtio-mmio.
> - * If using THP, then our minimal alignment becomes 2M.
> - * 2M trumps 64K, so let's go with that.
> - */
> - kvm->ram_size = kvm->cfg.ram_size;
> - kvm->arch.ram_alloc_size = kvm->ram_size + SZ_2M;
> - kvm->arch.ram_alloc_start = mmap_anon_or_hugetlbfs(kvm,
> - kvm->cfg.hugetlbfs_path,
> - kvm->arch.ram_alloc_size);
> -
> - if (kvm->arch.ram_alloc_start == MAP_FAILED)
> - die("Failed to map %lld bytes for guest memory (%d)",
> - kvm->arch.ram_alloc_size, errno);
> -
> - kvm->ram_start = (void *)ALIGN((unsigned long)kvm->arch.ram_alloc_start,
> - SZ_2M);
> -
> - madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
> - MADV_MERGEABLE);
> -
> - madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
> - MADV_HUGEPAGE);
> -
> /* Create the virtual GIC. */
> if (gic__create(kvm, kvm->cfg.arch.irqchip))
> die("Failed to create virtual GIC");
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