When a TDX guest runs on Hyper-V, the hv_netvsc driver's netvsc_init_buf() allocates buffers using vzalloc(), and needs to share the buffers with the host OS by calling set_memory_decrypted(), which is not working for vmalloc() yet. Add the support by handling the pages one by one. Co-developed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Acked-by: Kai Huang <kai.huang@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- Hi Boris, Kirill and all, This patch was posted on May 20, 2024: Link: https://lore.kernel.org/all/20240521021238.1803-1-decui%40microsoft.com The patch caused an issue to Kirill's kexec TDX patchset, so Kirill fixed it: Link: https://lore.kernel.org/all/uewczuxr5foiwe6wklhcgzi6ejfwgacxxoa67xadey62s46yro@quwpodezpxh5/ Kirill agreed that I should repost the patch with his fix combined, hence I'm posting this new version, which is based on tip's master today (at the moment, it's commit aa9d8caba6e4 ("Merge timers/core into tip/master")). I suppose the patch would go in the branch tip/master or x86/tdx. Thanks, Dexuan arch/x86/coco/tdx/tdx.c | 43 ++++++++++++++++++++++++++++++++++------- 1 file changed, 36 insertions(+), 7 deletions(-) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 078e2bac25531..8f471260924f7 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -8,6 +8,7 @@ #include <linux/export.h> #include <linux/io.h> #include <linux/kexec.h> +#include <linux/mm.h> #include <asm/coco.h> #include <asm/tdx.h> #include <asm/vmx.h> @@ -782,6 +783,19 @@ static bool tdx_map_gpa(phys_addr_t start, phys_addr_t end, bool enc) return false; } +static bool tdx_enc_status_changed_phys(phys_addr_t start, phys_addr_t end, + bool enc) +{ + if (!tdx_map_gpa(start, end, enc)) + return false; + + /* shared->private conversion requires memory to be accepted before use */ + if (enc) + return tdx_accept_memory(start, end); + + return true; +} + /* * Inform the VMM of the guest's intent for this physical page: shared with * the VMM or private to the guest. The VMM is expected to change its mapping @@ -789,15 +803,30 @@ 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; + + /* Step through page-by-page for vmalloc() mappings */ + if (is_vmalloc_addr((void *)vaddr)) + step = PAGE_SIZE; + + for (addr = start; addr < end; addr += step) { + phys_addr_t start_pa; + phys_addr_t end_pa; + + /* The check fails on vmalloc() mappings */ + if (virt_addr_valid(addr)) + start_pa = __pa(addr); + else + start_pa = slow_virt_to_phys((void *)addr); - if (!tdx_map_gpa(start, end, enc)) - return false; + end_pa = start_pa + step; - /* shared->private conversion requires memory to be accepted before use */ - if (enc) - return tdx_accept_memory(start, end); + if (!tdx_enc_status_changed_phys(start_pa, end_pa, enc)) + return false; + } return true; } -- 2.25.1
