Re: [PATCH] x86/tdx: Support vmalloc() for tdx_enc_status_changed()

On Mon, May 20, 2024 at 07:12:38PM -0700, Dexuan Cui wrote:

@@ -785,15 +799,22 @@ static bool tdx_map_gpa(phys_addr_t start, phys_addr_t end, bool enc) */ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) {

• phys_addr_t start = __pa(vaddr);
• phys_addr_t end = __pa(vaddr + numpages * PAGE_SIZE);

• unsigned long start = vaddr;
• unsigned long end = start + numpages * PAGE_SIZE;
• unsigned long step = end - start;
• unsigned long addr;

• if (!tdx_map_gpa(start, end, enc))

• return false;
  

• /* Step through page-by-page for vmalloc() mappings */
• if (is_vmalloc_addr((void *)vaddr))

• step = PAGE_SIZE;
  

• /* shared->private conversion requires memory to be accepted before use */
• if (enc)

• return tdx_accept_memory(start, end);
  

• for (addr = start; addr < end; addr += step) {

• phys_addr_t start_pa = slow_virt_to_phys((void *)addr);
  

• phys_addr_t end_pa   = start_pa + step;
  

• if (!tdx_enc_status_changed_phys(start_pa, end_pa, enc))
  

• 	return false;
  

• }

return true; }

This patch collied with kexec changes. tdx_kexec_finish() calls tdx_enc_status_changed() after clearing pte, so slow_virt_to_phys() crashes on in.

Daxuan, could you check if the fixup below works for you on vmalloc addresses?

diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index ef8ec2425998..5e455c883bcc 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -813,8 +813,15 @@ static bool tdx_enc_status_changed(unsigned long vaddr, int numpages, bool enc) step = PAGE_SIZE;

for (addr = start; addr < end; addr += step) { - phys_addr_t start_pa = slow_virt_to_phys((void *)addr); - phys_addr_t end_pa = start_pa + step; + phys_addr_t start_pa; + phys_addr_t end_pa; + + if (virt_addr_valid(addr)) + start_pa = __pa(addr); + else + start_pa = slow_virt_to_phys((void *)addr); + + end_pa = start_pa + step;

if (!tdx_enc_status_changed_phys(start_pa, end_pa, enc)) return false;