pKVM need to reserve its own memory for its data or runtime allocation,
such as pkvm data structure, page allocator data structure (vmemmap),
VMX pages, and MMU/EPT page table pages.
Implement hyp_total_reserve_pages to calculate total reserve page
numbers needed by pKVM.
Virtual memory map (vmemmap) for page allocator is calculated based on
system memory size.
3 extra pages for VMX - vmcs area to support VMXON, vmcs page to support
run host vcpu, and msr_bitmap to support msr emulation.
Consider the worst case for page table allocation pages. For host EPT,
allow extra 1 GiB for MMIO mappings.
Signed-off-by: Shaoqin Huang <shaoqin.huang@xxxxxxxxx>
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
Signed-off-by: Jason Chen CJ <jason.cj.chen@xxxxxxxxx>
---
arch/x86/include/asm/kvm_pkvm.h | 94 ++++++++++++++++++++++++++++
arch/x86/kvm/vmx/pkvm/hyp/memory.c | 4 ++
arch/x86/kvm/vmx/pkvm/include/pkvm.h | 2 +
arch/x86/kvm/vmx/pkvm/pkvm_host.c | 14 +++++
4 files changed, 114 insertions(+)
diff --git a/arch/x86/include/asm/kvm_pkvm.h b/arch/x86/include/asm/kvm_pkvm.h
index 480051f28ebc..30f7f805bcb8 100644
--- a/arch/x86/include/asm/kvm_pkvm.h
+++ b/arch/x86/include/asm/kvm_pkvm.h
@@ -8,6 +8,15 @@
#ifdef CONFIG_PKVM_INTEL
+#include <linux/memblock.h>
+#include <asm/pkvm_image.h>
+
+#define HYP_MEMBLOCK_REGIONS 128
+#define PKVM_PGTABLE_MAX_LEVELS 5U
+
+extern struct memblock_region pkvm_sym(hyp_memory)[];
+extern unsigned int pkvm_sym(hyp_memblock_nr);
+
void *pkvm_phys_to_virt(unsigned long phys);
unsigned long pkvm_virt_to_phys(void *virt);
@@ -18,6 +27,91 @@ unsigned long pkvm_virt_to_phys(void *virt);
#define __hyp_pa __pkvm_pa
#define __hyp_va __pkvm_va
+static inline unsigned long __pkvm_pgtable_max_pages(unsigned long nr_pages)
+{
+ unsigned long total = 0, i;
+
+ /* Provision the worst case */
+ for (i = 0; i < PKVM_PGTABLE_MAX_LEVELS; i++) {
+ nr_pages = DIV_ROUND_UP(nr_pages, PTRS_PER_PTE);
+ total += nr_pages;
+ }
+
+ return total;
+}
+
+static inline unsigned long __pkvm_pgtable_total_pages(void)
+{
+ unsigned long total = 0, i;
+
+ for (i = 0; i < pkvm_sym(hyp_memblock_nr); i++) {
+ struct memblock_region *reg = &pkvm_sym(hyp_memory)[i];
+
+ total += __pkvm_pgtable_max_pages(reg->size >> PAGE_SHIFT);
+ }
+
+ return total;
+}
+
+static inline unsigned long host_ept_pgtable_pages(void)
+{
+ unsigned long res;
+
+ /*
+ * Include an extra 16 pages to safely upper-bound the worst case of
+ * concatenated pgds.
+ */
+ res = __pkvm_pgtable_total_pages() + 16;
+
+ /* Allow 1 GiB for MMIO mappings */
+ res += __pkvm_pgtable_max_pages(SZ_1G >> PAGE_SHIFT);
+
+ return res;
+}
+
+static inline unsigned long pkvm_mmu_pgtable_pages(void)
+{
+ unsigned long res;
+
+ res = __pkvm_pgtable_total_pages();
+
+ return res;
+}
+
+static inline unsigned long pkvm_vmemmap_memblock_size(struct memblock_region *reg,
+ size_t vmemmap_entry_size)
+{
+ unsigned long nr_pages = reg->size >> PAGE_SHIFT;
+ unsigned long start, end;
+
+ /* Translate the pfn to the vmemmap entry */
+ start = (reg->base >> PAGE_SHIFT) * vmemmap_entry_size;
+ end = start + nr_pages * vmemmap_entry_size;
+ start = ALIGN_DOWN(start, PAGE_SIZE);
+ end = ALIGN(end, PAGE_SIZE);
+
+ return end - start;
+}
+
+static inline unsigned long pkvm_vmemmap_pages(size_t vmemmap_entry_size)
+{
+ unsigned long total_size = 0, i;
+
+ for (i = 0; i < pkvm_sym(hyp_memblock_nr); i++) {
+ total_size += pkvm_vmemmap_memblock_size(&pkvm_sym(hyp_memory)[i],
+ vmemmap_entry_size);
+ }
+
+ return total_size >> PAGE_SHIFT;
+}
+
+static inline unsigned long pkvm_data_struct_pages(unsigned long global_pgs,
+ unsigned long percpu_pgs, int num_cpus)
+{
+ return (percpu_pgs * num_cpus + global_pgs);
+}
+
+u64 hyp_total_reserve_pages(void);
#endif
#endif
diff --git a/arch/x86/kvm/vmx/pkvm/hyp/memory.c b/arch/x86/kvm/vmx/pkvm/hyp/memory.c
index 62dd80947d8e..eb913cf08691 100644
--- a/arch/x86/kvm/vmx/pkvm/hyp/memory.c
+++ b/arch/x86/kvm/vmx/pkvm/hyp/memory.c
@@ -4,10 +4,14 @@
*/
#include <linux/types.h>
+#include <asm/kvm_pkvm.h>
unsigned long __page_base_offset;
unsigned long __symbol_base_offset;
+unsigned int hyp_memblock_nr;
+struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS];
+
void *pkvm_phys_to_virt(unsigned long phys)
{
return (void *)__page_base_offset + phys;
diff --git a/arch/x86/kvm/vmx/pkvm/include/pkvm.h b/arch/x86/kvm/vmx/pkvm/include/pkvm.h
index b344165511f7..1c2b70c3788e 100644
--- a/arch/x86/kvm/vmx/pkvm/include/pkvm.h
+++ b/arch/x86/kvm/vmx/pkvm/include/pkvm.h
@@ -47,6 +47,8 @@ struct pkvm_hyp {
#define PKVM_PAGES (ALIGN(sizeof(struct pkvm_hyp), PAGE_SIZE) >> PAGE_SHIFT)
#define PKVM_PCPU_PAGES (ALIGN(sizeof(struct pkvm_pcpu), PAGE_SIZE) >> PAGE_SHIFT)
#define PKVM_HOST_VCPU_PAGES (ALIGN(sizeof(struct pkvm_host_vcpu), PAGE_SIZE) >> PAGE_SHIFT)
+#define PKVM_VMCS_PAGES 3 /*vmxarea+vmcs+msr_bitmap*/
+#define PKVM_PERCPU_PAGES (PKVM_PCPU_PAGES + PKVM_HOST_VCPU_PAGES + PKVM_VMCS_PAGES)
extern char __pkvm_text_start[], __pkvm_text_end[];
diff --git a/arch/x86/kvm/vmx/pkvm/pkvm_host.c b/arch/x86/kvm/vmx/pkvm/pkvm_host.c
index 9705aebaab2e..655ee8da2ac2 100644
--- a/arch/x86/kvm/vmx/pkvm/pkvm_host.c
+++ b/arch/x86/kvm/vmx/pkvm/pkvm_host.c
@@ -6,8 +6,10 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/trapnr.h>
+#include <asm/kvm_pkvm.h>
#include <pkvm.h>
+#include "pkvm_constants.h"
MODULE_LICENSE("GPL");
@@ -29,6 +31,18 @@ static struct gdt_page pkvm_gdt_page = {
},
};
+u64 hyp_total_reserve_pages(void)
+{
+ u64 total;
+
+ total = pkvm_data_struct_pages(PKVM_PAGES, PKVM_PERCPU_PAGES, num_possible_cpus());
+ total += pkvm_vmemmap_pages(PKVM_VMEMMAP_ENTRY_SIZE);
+ total += pkvm_mmu_pgtable_pages();
+ total += host_ept_pgtable_pages();
+
+ return total;
+}
+
static void *pkvm_early_alloc_contig(int pages)
{
return alloc_pages_exact(pages << PAGE_SHIFT, GFP_KERNEL | __GFP_ZERO);
--
2.25.1
