On Wed, Jul 10, 2019 at 08:13:11PM +0000, Singh, Brijesh wrote: > Subject: Re: [PATCH v3 10/11] mm: x86: Invoke hypercall when page encryption > status is changed
Subject prefix: "x86/mm: Invoke ..." git log <filename> would usually show you how the prefixing should look like. > Invoke a hypercall when a memory region is changed from encrypted -> > decrypted and vice versa. Hypervisor need to know the page encryption > status during the guest migration. > > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: Paolo Bonzini <[email protected]> > Cc: "Radim Krčmář" <[email protected]> > Cc: Joerg Roedel <[email protected]> > Cc: Borislav Petkov <[email protected]> > Cc: Tom Lendacky <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Signed-off-by: Brijesh Singh <[email protected]> > --- > arch/x86/include/asm/mem_encrypt.h | 3 ++ > arch/x86/mm/mem_encrypt.c | 45 +++++++++++++++++++++++++++++- > arch/x86/mm/pageattr.c | 15 ++++++++++ > 3 files changed, 62 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/mem_encrypt.h > b/arch/x86/include/asm/mem_encrypt.h > index 0c196c47d621..6e654ab5a8e4 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -94,4 +94,7 @@ extern char __start_bss_decrypted[], __end_bss_decrypted[], > __start_bss_decrypte > > #endif /* __ASSEMBLY__ */ > > +extern void set_memory_enc_dec_hypercall(unsigned long vaddr, > + unsigned long size, bool enc); > + > #endif /* __X86_MEM_ENCRYPT_H__ */ > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index e0df96fdfe46..f3fda1de2869 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -15,6 +15,7 @@ > #include <linux/dma-direct.h> > #include <linux/swiotlb.h> > #include <linux/mem_encrypt.h> > +#include <linux/kvm_para.h> > > #include <asm/tlbflush.h> > #include <asm/fixmap.h> > @@ -25,6 +26,7 @@ > #include <asm/processor-flags.h> > #include <asm/msr.h> > #include <asm/cmdline.h> > +#include <asm/kvm_para.h> > > #include "mm_internal.h" > > @@ -192,6 +194,45 @@ void __init sme_early_init(void) > swiotlb_force = SWIOTLB_FORCE; > } > > +void set_memory_enc_dec_hypercall(unsigned long vaddr, unsigned long sz, > bool enc) > +{ > + unsigned long vaddr_end, vaddr_next; > + > + vaddr_end = vaddr + sz; > + > + for (; vaddr < vaddr_end; vaddr = vaddr_next) { > + int psize, pmask, level; > + unsigned long pfn; > + pte_t *kpte; > + > + kpte = lookup_address(vaddr, &level); > + if (!kpte || pte_none(*kpte)) > + return; > + > + switch (level) { > + case PG_LEVEL_4K: > + pfn = pte_pfn(*kpte); > + break; > + case PG_LEVEL_2M: > + pfn = pmd_pfn(*(pmd_t *)kpte); > + break; > + case PG_LEVEL_1G: > + pfn = pud_pfn(*(pud_t *)kpte); > + break; > + default: > + return; > + } > + > + psize = page_level_size(level); > + pmask = page_level_mask(level); > + > + kvm_sev_hypercall3(KVM_HC_PAGE_ENC_STATUS, > + pfn << PAGE_SHIFT, psize >> PAGE_SHIFT, enc); > + > + vaddr_next = (vaddr & pmask) + psize; > + } > +} > + > static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc) > { > pgprot_t old_prot, new_prot; > @@ -249,12 +290,13 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int > level, bool enc) > static int __init early_set_memory_enc_dec(unsigned long vaddr, > unsigned long size, bool enc) > { > - unsigned long vaddr_end, vaddr_next; > + unsigned long vaddr_end, vaddr_next, start; > unsigned long psize, pmask; > int split_page_size_mask; > int level, ret; > pte_t *kpte; > > + start = vaddr; > vaddr_next = vaddr; > vaddr_end = vaddr + size; > > @@ -309,6 +351,7 @@ static int __init early_set_memory_enc_dec(unsigned long > vaddr, > > ret = 0; > > + set_memory_enc_dec_hypercall(start, size, enc); That function iterates the same way over the virtual addresses as early_set_memory_enc_dec() does. Please call kvm_sev_hypercall3(), wrapped of course, directly from early_set_memory_enc_dec(), for each iteration of the loop instead of iterating over all the virtual addresses a second time in set_memory_enc_dec_hypercall(). -- Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 247165, AG München
