From: Patrick Bridges Date: Thu, 12 Aug 2010 17:23:22 +0000 (-0600) Subject: Added support for using large shadow pages with 32-bit 4MB page table entries X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=ada3ad58ddc6747ea1062d6e9509a978389924c9;p=palacios.git Added support for using large shadow pages with 32-bit 4MB page table entries --- diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h index 10c3f9d..83bfb10 100644 --- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h +++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h @@ -46,8 +46,11 @@ static inline int activate_shadow_pt_32(struct guest_info * core) { * * * * */ -static int handle_4MB_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code, - pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde); +static int handle_4MB_shadow_pagefault_pde_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code, + pt_access_status_t shadow_pde_access, pde32_4MB_t * large_shadow_pde, + pde32_4MB_t * large_guest_pde); +static int handle_4MB_shadow_pagefault_pte_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code, + pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde); static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code, pte32_t * shadow_pt, pte32_t * guest_pt); @@ -129,6 +132,28 @@ static inline int handle_shadow_pagefault_32(struct guest_info * info, addr_t fa // Get the next shadow page level, allocate if not present if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) { + + if (info->use_large_pages && guest_pde->large_page) { + // Check underlying physical memory map to see if a large page is viable + addr_t guest_pa = BASE_TO_PAGE_ADDR_4MB(((pde32_4MB_t *)guest_pde)->page_base_addr); + addr_t host_pa; + if (v3_get_max_page_size(info, guest_pa, PAGE_SIZE_4MB) < PAGE_SIZE_4MB) { + PrintDebug("Underlying physical memory map doesn't allow use of a large page.\n"); + // Fallthrough to small pages + } else if ((v3_gpa_to_hpa(info, guest_pa, &host_pa) != 0) + || (v3_compute_page_alignment(host_pa) < PAGE_SIZE_4MB)) { + PrintDebug("Host memory alignment doesn't allow use of a large page.\n"); + // Fallthrough to small pages + } else if (handle_4MB_shadow_pagefault_pde_32(info, fault_addr, error_code, shadow_pde_access, + (pde32_4MB_t *)shadow_pde, (pde32_4MB_t *)guest_pde) == 0) { + return 0; + } else { + PrintError("Error handling large pagefault with large page\n"); + return -1; + } + // Fallthrough to handle the region with small pages + } + struct shadow_page_data * shdw_page = create_new_shadow_pt(info); shadow_pt = (pte32_t *)V3_VAddr((void *)shdw_page->page_pa); @@ -181,7 +206,7 @@ static inline int handle_shadow_pagefault_32(struct guest_info * info, addr_t fa return -1; } } else { - if (handle_4MB_shadow_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) { + if (handle_4MB_shadow_pagefault_pte_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) { PrintError("Error handling large pagefault\n"); return -1; } @@ -322,9 +347,8 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault return 0; } - - -static int handle_4MB_shadow_pagefault_32(struct guest_info * info, +// Handle a 4MB page fault with small pages in the PTE +static int handle_4MB_shadow_pagefault_pte_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code, pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde) { @@ -414,20 +438,98 @@ static int handle_4MB_shadow_pagefault_32(struct guest_info * info, return -1; } - PrintDebug("Returning from large page fault handler\n"); + PrintDebug("Returning from large page->small page fault handler\n"); return 0; } +// Handle a 4MB page fault with a 4MB page in the PDE +static int handle_4MB_shadow_pagefault_pde_32(struct guest_info * info, + addr_t fault_addr, pf_error_t error_code, + pt_access_status_t shadow_pde_access, + pde32_4MB_t * large_shadow_pde, pde32_4MB_t * large_guest_pde) +{ + addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr); + + + PrintDebug("Handling 4MB fault with large page (guest_fault_pa=%p) (error_code=%x)\n", (void *)guest_fault_pa, *(uint_t*)&error_code); + PrintDebug("LargeShadowPDE=%p, LargeGuestPDE=%p\n", large_shadow_pde, large_guest_pde); + + struct v3_mem_region * shdw_reg = v3_get_mem_region(info->vm_info, info->cpu_id, guest_fault_pa); + + + if (shdw_reg == NULL) { + // Inject a machine check in the guest + PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa); + v3_raise_exception(info, MC_EXCEPTION); + return -1; + } + + if (shadow_pde_access == PT_ACCESS_OK) { + // Inconsistent state... + // Guest Re-Entry will flush tables and everything should now workd + PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n"); + return 0; + } + + + if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) { + // Get the guest physical address of the fault + + if ((shdw_reg->flags.alloced == 1) && + (shdw_reg->flags.read == 1)) { + addr_t shadow_pa = 0; + + if (v3_gpa_to_hpa(info, guest_fault_pa, &shadow_pa) == -1) { + PrintError("could not translate page fault address (%p)\n", (void *)guest_fault_pa); + return -1; + } + PrintDebug("\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr)); + large_guest_pde->vmm_info = V3_LARGE_PG; /* For invalidations */ + large_shadow_pde->page_base_addr = PAGE_BASE_ADDR_4MB(shadow_pa); + large_shadow_pde->large_page = 1; + large_shadow_pde->present = 1; + large_shadow_pde->user_page = 1; + if (shdw_reg->flags.write == 0) { + large_shadow_pde->writable = 0; + } else { + large_shadow_pde->writable = 1; + } + //set according to VMM policy + large_shadow_pde->write_through = large_guest_pde->write_through; + large_shadow_pde->cache_disable = large_guest_pde->cache_disable; + large_shadow_pde->global_page = large_guest_pde->global_page; + // + } else { + if (shdw_reg->unhandled(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) { + PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr); + return -1; + } + } + } else if (shadow_pde_access == PT_ACCESS_WRITE_ERROR) { + if (shdw_reg->flags.write == 0) { + if (shdw_reg->unhandled(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) { + PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr); + return -1; + } + } + } else { + PrintError("Error in large page fault handler...\n"); + PrintError("This case should have been handled at the top level handler\n"); + return -1; + } + PrintDebug("Returning from large page->large page fault handler\n"); + return 0; +} /* If we start to optimize we should look up the guest pages in the cache... */ static inline int handle_shadow_invlpg_32(struct guest_info * info, addr_t vaddr) {