Messages in this thread |  | | Subject | Re: [PATCH v8 13/40] x86/kernel: Make the bss.decrypted section shared in RMP table | From | Brijesh Singh <> | Date | Wed, 5 Jan 2022 13:52:14 -0600 |
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On 1/4/22 11:56 AM, Venu Busireddy wrote: > On 2021-12-10 09:43:05 -0600, Brijesh Singh wrote: >> The encryption attribute for the bss.decrypted region is cleared in the >> initial page table build. This is because the section contains the data >> that need to be shared between the guest and the hypervisor. >> >> When SEV-SNP is active, just clearing the encryption attribute in the >> page table is not enough. The page state need to be updated in the RMP >> table. >> >> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> >> --- >> arch/x86/kernel/head64.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c >> index fa02402dcb9b..72c5082a3ba4 100644 >> --- a/arch/x86/kernel/head64.c >> +++ b/arch/x86/kernel/head64.c >> @@ -143,7 +143,14 @@ static unsigned long sme_postprocess_startup(struct boot_params *bp, pmdval_t *p >> if (sme_get_me_mask()) { >> vaddr = (unsigned long)__start_bss_decrypted; >> vaddr_end = (unsigned long)__end_bss_decrypted; >> + >> for (; vaddr < vaddr_end; vaddr += PMD_SIZE) { >> + /* >> + * When SEV-SNP is active then transition the page to shared in the RMP >> + * table so that it is consistent with the page table attribute change. >> + */ >> + early_snp_set_memory_shared(__pa(vaddr), __pa(vaddr), PTRS_PER_PMD); > > Shouldn't the first argument be vaddr as below? >
Nope, sme_postprocess_startup() is called while we are fixing the initial page table and running with identity mapping (so va == pa).
thanks
> early_snp_set_memory_shared(vaddr, __pa(vaddr), PTRS_PER_PMD); > > Venu >
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