Re: [PATCH Part1 RFC v4 09/36] x86/compressed: Add helper for validating pages in the decompression stage
From: Borislav Petkov <bp@alien8.de>
Date: 2021-08-13 10:22:29
Also in:
kvm, linux-coco, linux-crypto, linux-mm, lkml, platform-driver-x86
On Wed, Jul 07, 2021 at 01:14:39PM -0500, Brijesh Singh wrote:
quoted hunk ↗ jump to hunk
@@ -274,16 +274,31 @@ static int set_clr_page_flags(struct x86_mapping_info *info, /* * Changing encryption attributes of a page requires to flush it from * the caches. + * + * If the encryption attribute is being cleared, then change the page + * state to shared in the RMP table.
That comment...
*/
- if ((set | clr) & _PAGE_ENC)
+ if ((set | clr) & _PAGE_ENC) {
clflush_page(address);
... goes here: <---
+ if (clr) + snp_set_page_shared(pte_pfn(*ptep) << PAGE_SHIFT); + } +
...
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index 2f3081e9c78c..f386d45a57b6 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c@@ -164,6 +164,47 @@ static bool is_vmpl0(void) return true; } +static void __page_state_change(unsigned long paddr, int op)
That op should be:
enum psc_op {
SNP_PAGE_STATE_SHARED,
SNP_PAGE_STATE_PRIVATE,
};
and have
static void __page_state_change(unsigned long paddr, enum psc_op op)
so that the compiler can check you're at least passing from the correct
set of defines.
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h index ea508835ab33..aee07d1bb138 100644 --- a/arch/x86/include/asm/sev-common.h +++ b/arch/x86/include/asm/sev-common.h@@ -45,6 +45,23 @@ (((unsigned long)reg & GHCB_MSR_CPUID_REG_MASK) << GHCB_MSR_CPUID_REG_POS) | \ (((unsigned long)fn) << GHCB_MSR_CPUID_FUNC_POS)) +/* SNP Page State Change */ +#define GHCB_MSR_PSC_REQ 0x014 +#define SNP_PAGE_STATE_PRIVATE 1 +#define SNP_PAGE_STATE_SHARED 2 +#define GHCB_MSR_PSC_GFN_POS 12 +#define GHCB_MSR_PSC_GFN_MASK GENMASK_ULL(39, 0) +#define GHCB_MSR_PSC_OP_POS 52 +#define GHCB_MSR_PSC_OP_MASK 0xf +#define GHCB_MSR_PSC_REQ_GFN(gfn, op) \ + (((unsigned long)((op) & GHCB_MSR_PSC_OP_MASK) << GHCB_MSR_PSC_OP_POS) | \ + ((unsigned long)((gfn) & GHCB_MSR_PSC_GFN_MASK) << GHCB_MSR_PSC_GFN_POS) | \ + GHCB_MSR_PSC_REQ) + +#define GHCB_MSR_PSC_RESP 0x015 +#define GHCB_MSR_PSC_ERROR_POS 32 +#define GHCB_MSR_PSC_RESP_VAL(val) ((val) >> GHCB_MSR_PSC_ERROR_POS) +
Also get rid of eccessive defines...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette