In preparation for unmapping hyp pages from host stage-2, allocate/free hyp stack using new helpers which automatically mark the pages reserved.
Signed-off-by: David Brazdil <[email protected]> --- arch/arm64/kvm/arm.c | 49 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index d437052c5481..8a1fcf4dffca 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1453,13 +1453,58 @@ static int init_subsystems(void) return err; } +/* + * Alloc pages and mark them reserved so the kernel never tries to + * take them away from the hypervisor. + */ +static unsigned long alloc_hyp_pages(gfp_t flags, unsigned int order) +{ + struct page *page; + unsigned long i; + + page = alloc_pages(flags, order); + if (!page) + return 0; + + for (i = 0; i < (1ul << order); ++i) + mark_page_reserved(page + i); + + return (unsigned long)page_address(page); +} + +static unsigned long alloc_hyp_page(gfp_t flags) +{ + return alloc_hyp_pages(flags, 0); +} + +/* + * Free pages which were previously marked reserved for the hypervisor. + */ +static void free_hyp_pages(unsigned long addr, unsigned int order) +{ + unsigned long i; + struct page *page; + + if (!addr) + return; + + page = virt_to_page(addr); + for (i = 0; i < (1ul << order); ++i) + free_reserved_page(page + i); +} + +static void free_hyp_page(unsigned long addr) +{ + return free_hyp_pages(addr, 0); +} + static void teardown_hyp_mode(void) { int cpu; free_hyp_pgds(); for_each_possible_cpu(cpu) - free_page(per_cpu(kvm_arm_hyp_stack_page, cpu)); + free_hyp_page(per_cpu(kvm_arm_hyp_stack_page, cpu)); } /** @@ -1483,7 +1528,7 @@ static int init_hyp_mode(void) for_each_possible_cpu(cpu) { unsigned long stack_page; - stack_page = __get_free_page(GFP_KERNEL); + stack_page = alloc_hyp_page(GFP_KERNEL); if (!stack_page) { err = -ENOMEM; goto out_err; -- 2.28.0.402.g5ffc5be6b7-goog
