| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20240705142607.GAZogCf61FRALJxHGZ@fat_crate.local>
Date: Fri, 5 Jul 2024 16:26:07 +0200
From: Borislav Petkov <bp@...en8.de>
To: Ashish Kalra <Ashish.Kalra@....com>
Cc: dave.hansen@...ux.intel.com, tglx@...utronix.de, mingo@...hat.com,
x86@...nel.org, hpa@...or.com, rafael@...nel.org,
peterz@...radead.org, adrian.hunter@...el.com,
sathyanarayanan.kuppuswamy@...ux.intel.com, jun.nakajima@...el.com,
kirill.shutemov@...ux.intel.com, rick.p.edgecombe@...el.com,
linux-kernel@...r.kernel.org, thomas.lendacky@....com,
michael.roth@....com, seanjc@...gle.com, kai.huang@...el.com,
bhe@...hat.com, bdas@...hat.com, vkuznets@...hat.com,
dionnaglaze@...gle.com, anisinha@...hat.com, ardb@...nel.org,
dyoung@...hat.com, kexec@...ts.infradead.org,
linux-coco@...ts.linux.dev, jroedel@...e.de
Subject: Re: [PATCH v11 2/3] x86/mm: refactor __set_clr_pte_enc()
On Tue, Jul 02, 2024 at 07:57:54PM +0000, Ashish Kalra wrote:
> From: Ashish Kalra <ashish.kalra@....com>
>
> Refactor __set_clr_pte_enc() and add two new helper functions to
> set/clear PTE C-bit from early SEV/SNP initialization code and
> later during normal system operations and shutdown/kexec.
>
> Signed-off-by: Ashish Kalra <ashish.kalra@....com>
> ---
> arch/x86/include/asm/sev.h | 9 +++++++
> arch/x86/mm/mem_encrypt_amd.c | 47 +++++++++++++++++++++++++++++------
> 2 files changed, 48 insertions(+), 8 deletions(-)
Some serious cleanups ontop which reduce the diffstat even more. Untested ofc.
Holler if something's unclear.
---
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 0c90a8a74a88..5013c3afb0c4 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1012,11 +1012,14 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end)
static void set_pte_enc(pte_t *kpte, int level, void *va)
{
- unsigned long pfn;
- pgprot_t new_prot;
-
- prep_set_clr_pte_enc(kpte, level, 1, va, &pfn, NULL, NULL, &new_prot);
- set_pte_enc_mask(kpte, pfn, new_prot);
+ struct pte_enc_desc d = {
+ .kpte = kpte,
+ .pte_level = level,
+ .va = va
+ };
+
+ prepare_pte_enc(&d);
+ set_pte_enc_mask(kpte, d.pfn, d.new_pgprot);
}
static bool make_pte_private(pte_t *pte, unsigned long addr, int pages, int level)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 4f1a6d1e3f4c..68a03fd07665 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -234,6 +234,22 @@ struct svsm_attest_call {
u8 rsvd[4];
};
+/* PTE descriptor used for the prepare_pte_enc() operations. */
+struct pte_enc_desc {
+ pte_t *kpte;
+ int pte_level;
+ bool encrypt;
+ /* pfn of the kpte above */
+ unsigned long pfn;
+ /* physical address of @pfn */
+ unsigned long pa;
+ /* virtual address of @pfn */
+ void *va;
+ /* memory covered by the pte */
+ unsigned long size;
+ pgprot_t new_pgprot;
+};
+
/*
* SVSM protocol structure
*/
@@ -348,9 +364,7 @@ u64 snp_get_unsupported_features(u64 status);
u64 sev_get_status(void);
void sev_show_status(void);
void snp_update_svsm_ca(void);
-int prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va,
- unsigned long *ret_pfn, unsigned long *ret_pa,
- unsigned long *ret_size, pgprot_t *ret_new_prot);
+int prepare_pte_enc(struct pte_enc_desc *d);
void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot);
void snp_kexec_finish(void);
void snp_kexec_begin(void);
@@ -390,10 +404,7 @@ static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
static inline u64 sev_get_status(void) { return 0; }
static inline void sev_show_status(void) { }
static inline void snp_update_svsm_ca(void) { }
-static inline int
-prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va,
- unsigned long *ret_pfn, unsigned long *ret_pa,
- unsigned long *ret_size, pgprot_t *ret_new_prot) { }
+static inline int prepare_pte_enc(struct pte_enc_desc *d) { }
static inline void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot) { }
static inline void snp_kexec_finish(void) { }
static inline void snp_kexec_begin(void) { }
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index dec24bb08b09..774f9677458f 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -311,48 +311,37 @@ static int amd_enc_status_change_finish(unsigned long vaddr, int npages, bool en
return 0;
}
-int prep_set_clr_pte_enc(pte_t *kpte, int level, int enc, void *va,
- unsigned long *ret_pfn, unsigned long *ret_pa,
- unsigned long *ret_size, pgprot_t *ret_new_prot)
+int prepare_pte_enc(struct pte_enc_desc *d)
{
- pgprot_t old_prot, new_prot;
- unsigned long pfn, pa, size;
+ pgprot_t old_prot;
- pfn = pg_level_to_pfn(level, kpte, &old_prot);
- if (!pfn)
+ d->pfn = pg_level_to_pfn(d->pte_level, d->kpte, &old_prot);
+ if (!d->pfn)
return 1;
- new_prot = old_prot;
- if (enc)
- pgprot_val(new_prot) |= _PAGE_ENC;
+ d->new_pgprot = old_prot;
+ if (d->encrypt)
+ pgprot_val(d->new_pgprot) |= _PAGE_ENC;
else
- pgprot_val(new_prot) &= ~_PAGE_ENC;
+ pgprot_val(d->new_pgprot) &= ~_PAGE_ENC;
/* If prot is same then do nothing. */
- if (pgprot_val(old_prot) == pgprot_val(new_prot))
+ if (pgprot_val(old_prot) == pgprot_val(d->new_pgprot))
return 1;
- pa = pfn << PAGE_SHIFT;
- size = page_level_size(level);
+ d->pa = d->pfn << PAGE_SHIFT;
+ d->size = page_level_size(d->pte_level);
/*
- * We are going to perform in-place en-/decryption and change the
- * physical page attribute from C=1 to C=0 or vice versa. Flush the
- * caches to ensure that data gets accessed with the correct C-bit.
+ * In-place en-/decryption and physical page attribute change
+ * from C=1 to C=0 or vice versa will be performed. Flush the
+ * caches to ensure that data gets accessed with the correct
+ * C-bit.
*/
- if (va)
- clflush_cache_range(va, size);
+ if (d->va)
+ clflush_cache_range(d->va, d->size);
else
- clflush_cache_range(__va(pa), size);
-
- if (ret_new_prot)
- *ret_new_prot = new_prot;
- if (ret_size)
- *ret_size = size;
- if (ret_pfn)
- *ret_pfn = pfn;
- if (ret_pa)
- *ret_pa = pa;
+ clflush_cache_range(__va(d->pa), d->size);
return 0;
}
@@ -368,33 +357,36 @@ void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot)
static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
{
- unsigned long pfn, pa, size;
- pgprot_t new_prot;
+ struct pte_enc_desc d = {
+ .kpte = kpte,
+ .pte_level = level,
+ .encrypt = enc
+ };
- if (prep_set_clr_pte_enc(kpte, level, enc, NULL, &pfn, &pa, &size, &new_prot))
+ if (prepare_pte_enc(&d))
return;
/* Encrypt/decrypt the contents in-place */
if (enc) {
- sme_early_encrypt(pa, size);
+ sme_early_encrypt(d.pa, d.size);
} else {
- sme_early_decrypt(pa, size);
+ sme_early_decrypt(d.pa, d.size);
/*
* ON SNP, the page state in the RMP table must happen
* before the page table updates.
*/
- early_snp_set_memory_shared((unsigned long)__va(pa), pa, 1);
+ early_snp_set_memory_shared((unsigned long)__va(d.pa), d.pa, 1);
}
- set_pte_enc_mask(kpte, pfn, new_prot);
+ set_pte_enc_mask(kpte, d.pfn, d.new_pgprot);
/*
* If page is set encrypted in the page table, then update the RMP table to
* add this page as private.
*/
if (enc)
- early_snp_set_memory_private((unsigned long)__va(pa), pa, 1);
+ early_snp_set_memory_private((unsigned long)__va(d.pa), d.pa, 1);
}
static int __init early_set_memory_enc_dec(unsigned long vaddr,
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
Powered by blists - more mailing lists