On Mon, May 13, 2024 at 01:40:30PM +0000, Elias El Yandouzi wrote:
> From: Hongyan Xia <hongy...@amazon.com>
>
> Building a PV dom0 is allocating from the domheap but uses it like the
> xenheap. Use the pages as they should be.
>
> Signed-off-by: Hongyan Xia <hongy...@amazon.com>
> Signed-off-by: Julien Grall <jgr...@amazon.com>
> Signed-off-by: Elias El Yandouzi <elias...@amazon.com>
>
> ----
> Changes in V3:
> * Fold following patch 'x86/pv: Map L4 page table for shim domain'
>
> Changes in V2:
> * Clarify the commit message
> * Break the patch in two parts
>
> Changes since Hongyan's version:
> * Rebase
> * Remove spurious newline
>
> diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
> index 807296c280..ac910b438a 100644
> --- a/xen/arch/x86/pv/dom0_build.c
> +++ b/xen/arch/x86/pv/dom0_build.c
> @@ -382,6 +382,10 @@ int __init dom0_construct_pv(struct domain *d,
> l3_pgentry_t *l3tab = NULL, *l3start = NULL;
> l2_pgentry_t *l2tab = NULL, *l2start = NULL;
> l1_pgentry_t *l1tab = NULL, *l1start = NULL;
> + mfn_t l4start_mfn = INVALID_MFN;
> + mfn_t l3start_mfn = INVALID_MFN;
> + mfn_t l2start_mfn = INVALID_MFN;
> + mfn_t l1start_mfn = INVALID_MFN;
>
> /*
> * This fully describes the memory layout of the initial domain. All
> @@ -710,22 +714,32 @@ int __init dom0_construct_pv(struct domain *d,
> v->arch.pv.event_callback_cs = FLAT_COMPAT_KERNEL_CS;
> }
>
> +#define UNMAP_MAP_AND_ADVANCE(mfn_var, virt_var, maddr) \
> +do { \
> + unmap_domain_page(virt_var); \
> + mfn_var = maddr_to_mfn(maddr); \
> + maddr += PAGE_SIZE; \
> + virt_var = map_domain_page(mfn_var); \
FWIW, I would do the advance after the map, so that the order matches
the name of the function.
> +} while ( false )
> +
> if ( !compat )
> {
> maddr_to_page(mpt_alloc)->u.inuse.type_info = PGT_l4_page_table;
> - l4start = l4tab = __va(mpt_alloc); mpt_alloc += PAGE_SIZE;
> + UNMAP_MAP_AND_ADVANCE(l4start_mfn, l4start, mpt_alloc);
> + l4tab = l4start;
You could even make the macro return virt_var, and so use it like:
l4tab = l4start = UNMAP_MAP_AND_ADVANCE(l4start_mfn, mpt_alloc);
?
Anyway, no strong opinion.
Thanks, Roger.
